Physics
for
CSEC®
Physics
for
CSEC®
Lancelot
Darren
Yvette
Earl
Caesar
Forbes
Mayers
Skerritt
3
Great
Clarendon
Oxford
It
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furthers
and
Oxford
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®
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Acknowledgements
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Digital,
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published
This
Press
illustrations
moral
First
by
Darren
Council
Oxford,
University’s
University
Original
All
the
education
Text
Street,
websites
only.
contained
are
Oxford
in
any
provided
by
disclaims
third
party
Oxford
any
in
good
faith
responsibility
website
referenced
for
in
all
at
their
Contents
Introduction
Section
1.1
1
1
3
Waves
3.1
Wave
3.2
Describing
motion
76
3.3
Electromagnetic
3.4
Light
3.5
Reflection
3.6
Refraction
3.7
Refractive
3.8
Converging
3.9
Diverging
Mechanics
Base
units,
derived
units
and
Making
1.3
Variables
measurements
and
Graphical
Vectors
1.6
Forces
78
waves
80
2
1.2
1.5
waves
measuring
density
1.4
Section
graph
plotting
and
shadows
82
of
light
84
6
analysis
and
rays
4
of
light
86
8
scalars
index
and
total
internal
10
reflection
1.7
Moments
14
1.8
Stability
16
1.9
Investigating
Section
1
Hooke’s
Practice
law
exam
Moving
objects
and
lenses
lenses
3.10
Magnification
3.11
Diffraction,
90
and
the
eye
92
94
18
questions
1
interference
and
theories
20
about
1.10
88
12
the
nature
of
light
96
displacement–time
graphs
3.12
Sound
3.13
Experimenting
waves
98
22
1.11
Acceleration
1.12
Newton’s
and
velocity–time
1.13
Momentum
and
1.14
More
momentum
graphs
about
Section
1
of
motion
1.15
Energy
and
1.16
Energy
sources
exam
energy
waves
100
3
Practice
exam
questions
102
26
impulse
Practice
sound
24
Section
law
with
28
Section
4
Electricity
and
magnetism
30
questions
2
transformations
4.1
Static
4.2
Electric
electricity
4.3
Uses
4.4
Electric
4.5
Electrical
4.6
Simple
4.7
Series
4.8
Cells
4.9
Resistance
106
32
fields
and
the
Van
de
Graaff
34
generator
1.17
Potential
1.18
Conservation
1.19
Power
1.20
1.21
energy
and
of
electricity
and
kinetic
energy
energy
and
dangers
sinking
1
and
Practice
energy
and
Thermometers
2.3
The
density
current
energy
circuits
questions
and
and
kinetic
3
and
states
Heat
temperature
of
and
temperature
2.6
Changes
2.7
Heating,
2.8
Specific
116
Investigating
4.11
Circuit
current
and
potential
characteristics
124
analysis
Direct
4
126
Practice
current
and
4.13
Mains
electricity
state
and
and
evaporation
exam
questions
alternating
1
current
128
4.14
Mains
safety
4.15
Conversion
4.16
Logic
circuits
1
4.17
Logic
circuits
2
Convection
latent
heat
heat
the
Caribbean
130
132
a.c.
to
d.c.
136
62
138
140
66
currents
4
Practice
exam
questions
2
142
68
radiation
thermal
134
of
64
4.18
Permanent
magnets
4.19
Magnetic
4.20
Electromagnetism
4.21
Forces
4.22
Electromagnetic
144
70
energy
fields
146
transfer
principles
2
in
60
Section
Applying
122
4.10
54
conduction
Infra-red
120
58
cooling
2.12
118
batteries
56
of
2.11
circuits
scales 52
matter
latent
Thermal
parallel
50
capacity
Section
114
components
theory
laws
2.5
2.10
transformations
and
48
Section
2.9
112
46
4.12
Gas
110
42
exam
physics
2.2
2.4
electricity
40
efficiency
Thermal
Heat,
static
38
difference
2.1
of
44
Floating,
2
108
36
Pressure
Section
Section
for
148
72
Practice
exam
questions
from
magnetic
fields
150
74
4.23
4.24
The
d.c.
motor
induction
and
the
a.c.
152
generator
Transformers
Section
4
Practice
154
156
exam
questions
3
158
iii
Contents
Section
5
The
physics
5.1
Models
5.2
Electrons,
of
the
5.3
Radioactive
5.4
Nuclear
5.5
A
5.6
Nuclear
5.7
Applications
5.8
The
the
of
the
atom
atom
160
nucleus
and
the
periodic
table
decays
model
of
5
and
164
reactions
radioactive
decay
release
Section
iv
162
emissions
and
of
of
decay
half-life
radioisotopes
nuclear
Practice
energy
exam
questions
166
168
170
172
174
176
Glossary
178
Index
182
Acknowledgements
187
Introduction
This
Study
Guide
has
been
developed
exclusively

On
Your
Marks
activities
provide
sample
®
with
be
the
used
both
in
Caribbean
as
an
and
Examinations
additional
out
of
resource
school,
Council
by
following
(CXC
)
to
examination-style
candidates,
questions,
the
and
Caribbean
with
feedback
short
answer
example
from
an
and
candidate
examiner
to
essay
type
answers
show
where
®
Secondary
Education
Certificate
(CSEC
)
programme.
answers
build
It
has
been
prepared
by
a
team
with
expertise
could
your
be
improved.
understanding,
These
skill
activities
level
and
will
confidence
in
in
answering
examination
questions.
®
the
CSEC
The
contents
providing
Physics
you
the
for
syllabus,
to
are
tools
and
master
syllabus.
full
help
the
Do
key
achieve
concepts
the
examination.
support
included
remember
on
and
to
you
features
guidance
examination
designed
to
the
teaching
to
your
make
and
refer
course
learning
best
it
in
easier
your
revise
and
format!

this
includes
Study
Guide
electronic
developing
good
is
an
activities
interactive
to
examination
assist
CD
you
in
techniques:
activities
experience
sections
of
and
inside
are
questions
and
check
of
helpful
the
problem
Answers
can
Inside
Yourself
questions
for
syllabus
requirements
T
est
provide
requirements
to

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specifically
multiple-choice
feedback
study
guide
will
so
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to
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refer
that
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can
areas.
included
practice
your
own
on
the
exam
work
as
CD
for
summary
questions,
you
so
that
you
proceed.
which
This
unique
and
interactive
with
combination
invaluable
of
examination
support
to
focused
practice
help
you
syllabus
will
content
provide
reach
your
you
full
®
potential
in
CSEC
Physics.
1
1
Mechanics
1.1
Base
and
When
LEARNING
we
units,
measuring
measure
the
end
of
this
able
topic
should
be

state
and
use
units
and
prefixes
1.2
you

derive
units
measure
a
shaped
T
able
for
the
regularly
quantity
we
need
to
density
metres
or
The
length
1.2 m,
not
of
a
just
desk
include
should
be
the
given
units
as,
for
of
the
example,
1.2.
to:
range
of
Base
SI
A

a
units
OUTCOMES
measurement.
At
derived
quantities
density
and
set
of
been
are
of
units
seven
agreed
shown
units,
based
on
internationally.
in
T
able
the
They
metre,
are
kilogram
known
as
and
the
SI
second,
base
has
units
and
1.1.1.
irregularly
objects.
Derived
1.1.1
units
There
are
These
units
many
can
mathematical
Quantity
Base
unit
mass
kilogram
kg
length
metre
m
more
units
all
derived
be
in
relationships
addition
directly
and
to
the
from
seven
the
base
seven,
units.
based
on
definitions.
Symbol
For
example,
the
speed
of
an
object
distance
speed
is
moved
second
s
current
ampere
A
This
means
that
the
from
the
equation:
(m)
=
time
time
defined
unit
for
speed
(s)
is
a
distance
divided
by
a
time:
−1
metres
temperature
kelvin
K
amount
mole
mol
Every
of
substance
For
per
other
candela
(m s
derived
convenience
derived
luminous
second
units
quantity
(and
have
).
to
can
be
honour
been
given
worked
important
special
out
this
way.
scientists)
names.
For
some
example,
of
the
the
unit
cd
for
a
potential
difference
derived
from
the
base
units
would
be
intensity
2
m
−3
kg s
−1
A
.
This
unit
is
given
the
special
name
volt
(V).
ACTIVITY
Standard
The
SI
base
precise
units
have
definitions
or
very
To
derivations.
avoid
form
using
standard
very
form.
large
In
or
very
standard
small
form
numbers,
the
number
scientists
is
always
use
written
in
x
Find
out
what
these
are.
the
is
format
the
of
x
A
×
number
indicates
movement
to
10
of
,
where
places
to
movement
the
A
is
a
move
to
the
number
the
between
decimal
right
while
point.
a
0
A
negative
and
10
and
positive
value
x
value
indicates
left.
3

4500
is

0.0006
written
as
4.5
×
10
×
10
−4
is
written
as
6
Prefixes
Scientists
so
use
are
Figure
1.1.1
SI
units
were
used
in
a
often
set
shown
of
in
need
to
prefixes
T
able
use
very
which
1.1.2.
This
large
may
set
be
of
or
very
small
attached
prefixes
to
numbers
any
allows
a
unit.
These
quantity
all
6
8.4
the
in
calculations
designing
Tree
Transport
Kingston,
2
the
needed
Half-Way
Centre
Jamaica.
in
×
10
watts
to
be
written
as
8.4
megawatts
or
and
8.4 MW.
like
T
able
Using
units:
1.1.2
Prefix
The
density
scientific
cubic
of
Prefixes
for
SI
units
density
a
material
language
centimetre
this
of
is
the
is
the
how
mass
much
material.
per
unit
mass
The
volume.
there
equation
is
in
a
In
cubic
defining
Symbol
metre
density
or
12
tera
T
10
G
10
M
10
kilo
k
10
centi
c
10
m
10
micro
μ
10
nano
n
10
pico
p
10
is:
9
giga
mass
m
6
mega
density
Represents
non-
=
or
ρ
=
volume
V
3
−2
WORKED
EXAMPLE
1
−3
milli
−6
Find
the
derived
SI
unit
of
density.
−9
Mass
is
measured
in
kilograms
(kg).
Volume
is
measured
in
cubic
3
metres
The
(m
−12
).
equation
defining
density
shows
that
density
is
a
mass
−3
divided
by
a
volume
and
therefore
the
SI
unit
of
density
is
kg m
ACTIVITY
Use
Measuring
the
these
To
measure
measure
taking
technique
described
on
density
the
the
density
mass
appropriate
of
using
a
a
regularly
balance
measurements
shaped
and
for
then
the
object
you
calculate
dimensions
of
must
the
volume
and
using
by
a
pages
range
to
of
find
the
density
irregularly
shaped
objects.
a
formula.
To
a
measure
the
measuring
rise
by
the
rough
cylinder
volume
WORKED
A
volume
of
has
an
partly
the
EXAMPLE
stone
of
a
irregular
full
of
object,
water.
The
place
level
the
of
object
the
inside
water
25
25
20
20
15
15
10
10
5
5
will
object.
2
mass
of
30 g.
It
is
placed
in
a
measuring
3
cylinder
containing
20 cm
of
water
and
the
level
of
the
water
3
rises
The
to
the
24 cm
density
of
the
mark
stone
(Figure
is
mass
1.1.2).
found
using:
(g)
30 g
–3
=
=
3
volume
(cm
7.5 g cm
3
)
(24
–
20) cm
Figure
KEY
SUMMARY
Use
the
derived
POINTS
QUESTIONS
1
1
1.1.2
following
units
for
equations
velocity,
to
work
out
acceleration
the
and
set
appropriate
of
use
base
a
standard
units
(SI)
for
quantities.
force.
distance
velocity
Scientists
2
Units
for
most
quantities
=
are
time
derived
from
these
base
units.
change
acceleration
in
velocity
=
3
The
density
of
an
object
is
time
mass
force
=
mass
×
acceleration
given
by
density
=
volume
2
Write
these
quantities
milliamperes,
4.9
using
the
micromoles,
base
2400
unit
and
standard
picoseconds,
0.2
form:
83
gigavolt.
−3
and
the
unit
is
kg m
or
−3
g cm
3
1.2
Making
Common
LEARNING
At
the
end
should
be
select
of
this
able
an
topic
Length
you
to:

a
range
identify
and
to
of
measure
random
length
error
error
If
in
use
of
the
calculations
measured
the
have
smallest
a
with
a
ruler
resolution
difference
in
of
a
or
tape
1 mm.
reading
measure.
The
the
These
resolution
of
instrument
an
can
be
length
used.
needs
Callipers
gauge
to
have
micrometer
be
a
measured,
resolution
will
have
a
callipers
of
or
0.1 mm
resolution
of
a
micrometer
and
a
high
quality
0.01 mm.
number
figures
and
be
typically
is
smaller
screw
appropriate
significant
a
can
measurements

instrument
can
measure.
experiments
systematic
lengths
instruments
appropriate
instrument
in
measurements
OUTCOMES
Many

measurements
Time
in
answers.
Time
intervals
stopwatches
times
the
To
are
full
generally
have
more
a
measured
resolution
than
0.1
of
second,
with
0.01
it
a
digital
second
may
be
but,
stopwatch.
as
human
unnecessary
to
Many
reaction
measure
to
resolution.
measure
triggered
much
are
times
by
more
events
better
precisely,
such
response
as
the
we
can
breaking
use
of
a
automatic
stopwatches
light-beam.
These
have
times.
Mass
Mass
a
1.2.1
This
micrometer
used
of
a
to
measure
is
being
the
measured
known
pan
Figure
is
one
or,
balances
is
by
a
balance
more
often,
available,
Uncertainty
and
which
by
some
a
compares
top-pan
with
a
an
unknown
balance.
resolution
of
A
variety
mass
of
to
top-
0.01 g.
error
gauge
wire.
When
we
as
‘true
the
make
Systematic
could
or
the
have
a
Readings
leading
to
it
from
some
may
not
be
exactly
instruments
uncertainty
in
the
introduce
our
same
error
in
calculations.
error
systematic
device
measurement
value’.
measurements
A
a
error
is
usually
measurement
damaged
end
the
result
of
technique.
so
that
it
some
For
flaw
example,
shows
all
in
a
the
measuring
metre
lengths
as
rule
1 mm
too
short.
Systematic
true
Random
1.2.2
Human
a
factor
reaction
when
time
using
is
will
make
the
readings
shift
away
from
the
error
error
is
an
unpredictable
measurement
when
the
you
you
take
a
error
introduced
reading.
into
Sometimes
this
a
is
because
of
a
technique
use
such
as
poor
positioning
stopwatch.
while
4
recorded
measurement.
Random
Figure
errors
measuring
length
(Figure
1.2.3).
of
your
line
of
sight
Observer
ACTIVITY
Observer
Use
Line
of
sight
Line
of
a
range
of
instruments
sight
to
take
measurements
of
the
Bar
Metre
properties
rule
how
of
Correct
reading
left-hand
Figure
end
of
of
True
the
1.2.3
A
bar
line
reading
right-hand
of
sight
of
end
Incorrect
of
the
bar
of
the
reading
bar
due
to
of
right-hand
‘line
of
a
to
of
measure
sheet
of
errors
will
cause
the
be
scattered
around
the
b
A
Student
The
effects
of
random
error
can
be
reduced
by
B
true
55 °C
55 °C
value.
thickness
paper.
a
to
out
error
error
readings
Find
end
sight’
Student
Random
objects.
performing
repeat
True
readings
and
finding
a
mean
value.
Readings
which
were
slightly
too
value
high
will
tend
to
cancel
readings
which
were
slightly
too
low.
50 °C
50 °C
Accuracy
If
a
to
and
measurement
be
accurate.
without
precision
is
It
close
is
repeating
not
the
to
the
true
possible
to
value
know
measurement
of
if
several
a
a
quantity
reading
times
it
is
and
is
said
accurate
45 °C
45 °C
calculating
Precise
a
mean
value.
All
possible
systematic
errors
must
be
avoided.
If
(but
of
the
measurements
taken
are
close
to
the
mean
then
you
can
not
that
the
results
are
accurate)
(but
precise
readings
mean
measurement
show
value
of
very
the
is
little
a
measurement
difference.
They
where
are
all
all
very
of
the
close
1.2.4
Demonstrating
is
to
a
not
possible
to
systematic
precise
which
are
a
precision
accuracy
WORKED
the
EXAMPLE
readings.
obtain
error
(Figure
both
b
repeated
to
The
It
precise)
accurate.
and
A
not
be
Figure
confident
Accurate
all
results
(Figure
1.2.4b).
accurate
which
are
1.2.4a).
The
and
very
precise
Results
best
but
can
not
also
accurate
be
experiments
due
accurate
produce
but
results
precise.
diameter
bearing
is
of
small
measured
callipers
giving
6.4 mm.
Using
for
a
volume
a
with
value
the
gives
ball
of
formula
an
answer
3
of
Quoting
answers
137.258 mm
volume
to
significant
The
number
reflection
of
of
significant
how
certain
fi gures
you
are
you
of
quote
the
in
any
precision
answers
of
your
is
a
never
resolution
to
two
given
or
in
of
use
more
your
three
significant
instruments.
significant
questions
or
by
In
fi gures
than
general,
fi gures
unless
measuring
are
sensible
answers
more
should
signifi cant
by
be
You
the
The
1.4
number
of
volume
×
10
is
recorded
as
3
mm
given
figures
are
KEY
instruments.
1
SUMMARY
the
a
answer.
justifi ed
Record
figures.
2
should
.
POINTS
Systematic
errors
QUESTIONS
produce
amount
1
How
can
you
2
T
able
1.2.1
increase
the
accuracy
of
a
a
constant
of
uncertainty
in
measurement?
measurements.
shows
three
sets
of
results
for
the
measurement
of
2
the
diameter
of
a
metal
rod
of
true
diameter
5.0 mm.
Which
Random
a
of
results
are
accurate,
which
are
precise
and
which
are
errors
varying
amount
in
measurements.
1.2.1
3
Set
of
both?
uncertainty
T
able
produce
sets
a/mm
4.3
5.6
5.5
4.2
4.9
The
number
of
significant
5.1
figures
Set
b/mm
5.1
4.9
5.0
4.9
4.9
5.1
Set
c/mm
4.7
4.8
4.6
4.8
4.6
4.7
of
a
shown
calculation
indication
in
in
the
of
the
is
the
result
an
uncertainty
answer.
5
1.3
Variables
and
graph
plotting
Scientific
LEARNING
investigations
connections
At
the
end
should

be
select
of
this
able
an
topic
a
you
physicist
the
to:
independent
effect
investigate
dependent

identify
other
its
effect
on
highly
The
of
this
controlled
during
be
able
change
to
in
and
in
order
alter
behaviour
.
one
variable
In
to
in
an
reveal
an
ideal
experiment
experiment
and
see
isolation.
variables
independent
experimenter
control
variables
would
quantities
a
variable
and
between
variable
Key
and
are
OUTCOMES
to
variable
see
what
is
the
effect
variable
changing
which
it
has
is
on
manipulated
the
by
the
experiment.
an
The
dependent
variable
is
the
variable
which
is
expected
to
change
investigation
in

plot
an
accurate
and
response
explore
experiment
explaining
For
EXAM
of
connection
finding
cause
if
you
water
water,
allow
s
relation
ship
variable.
is
of
between
relationship
that
were
the
a
these
two
between
variables
them
and
in
then
relationship.
investigating
denser
it
will
the
be’
hypothesis
then
the
‘The
colder
independent
a
variable
as
this
changing
temperature
The
is
of
the
dependent
the
quantity
water
variable
you
as
this
would
expect
to
is
be
what
the
change
you
would
density
in
of
response
be
the
the
to
temperature.
the
one
varia
ble
depend
ent
the
us
be tween
indepe
nden
t
be
manipulating.
experim
ental
invest
igate
one
independent
TIP
desig
n
while
the
by
the
example,
sample
would
to
the
graph.
an
Good
altering
wellScientists
scaled
to
Control
variables
and
There
are
usually
a
wide
range
of
other
factors
that
need
to
be
taken
varia
ble
into
contro
lling
all
account
during
an
experiment
so
that
they
do
not
have
an
effect
on
other
the
varia
bles.
results.
designs
These
ensure
are
that
known
these
as
control
factors
do
variables.
not
alter
Good
during
the
experimental
experiment.
Graphs
WORKED
Find
out
if
container
cooling.
design
One
of
is
plot
the
colour
affects
Your
the
of
in
a
rate
of
experimental
should
ensure
that
to
the
are
kept
The
best
ways
graph
graph
to
show
(Figure
then
would
explanation
the
can
a
clear
then
be
try
given
1.3.1).
relationship
If
there
relationship
to
explain
then
the
is
has
how
a
between
clear
two
been
this
pattern
variables
demonstrated.
relationship
relationship
shown
is
occurs.
If
an
causal.
these
graph
plotting
takes
time
and
practice.
Use
these
tips
to
help
constant:
produce

a
Scientists
Perfect
factors
the
EXAMPLE
temperature
of
yours.
the

Use
a

When
sharp
pencil
and
ruler.
surroundings

The
size
of
the
label

The
volume
of
you
draw
the
axes
make
sure
you
leave
enough
space
to
containers
liquid
in
them
clearly.
the

Plot
the
independent

Plot
the
dependent

Plot
the
graph

Use
variable
on
the
x-axis
containers

Air
paper
as
so
possible
increments
possible.
6
variable
on
the
y-axis
flow
that
the
data
horizontally
of
2,
5
or
10
points
and
(or
occupy
as
much
of
the
graph
vertically.
their
multiples)
for
your
scales
if
a
8
Clamp
7
6
1–
s m/yticoleV
5
4
Thread
3
2
l
Maximum
1
a
swing
angle
about
of
10°
0
0
10
20
30
40
50
Time/s
Figure
1.3.1
A
well-drawn
up
the
graph
available
has
clearly
labelled
axes
and
the
data
points
fill
space.
ACTIVITY
Bob
A
pendulum
A
mass
is
a
simple
device
that
can
be
used
to
measure
time.
Pointer
on
the
end
of
a
thread
or
wire
is
allowed
to
swing
centre
from
side
swing
to
back
side
and
(Figure
forth
to
1.3.2).
the
One
same
complete
oscillation
at
freely
is
of
swing
a
b
position.
Stop
c
The
following
three
factors
may
affect
the
period
(time
it
takes
b
for
one
complete
oscillation).
b
Investigate
each
controlling
the
comparing
each
of
the
other
three
two.
factors
Collect
independently
data
and
plot
a
while
separate
graphs
Start
of
the
independent
variables
to
the
period.
One

Length

Mass

Initial
of
the
complete
Figure
Y
ou
of
the
angle
will
need
pendulum
of
to
use
the
data
to
produce
a
graph
in
the
next
b
+
c
1.3.2
Timing
a
pendulum
POINTS
QUESTIONS
about
An
the
following
hypotheses
and
outline
a
independent
variable
to
investigate
them.
For
each
one
identify
variable,
dependent
variable
and
variable
is
is
changed
an
investigation
to
clearly
see
independent
that
basic
during
experiment
the
+
topic.
a
Think
a
displacement
1
1
=
bob
KEY
SUMMARY
oscillation
thread
any
if
this
change
has
any
other
effect.
variables
you
will
have
to
control.
2
a
The
greater
the
current
in
a
light
bulb
the
brighter
it
will
A
dependent
variable
b
The
c
The
further
away
from
a
sound
you
are
the
quieter
it
will
the
force
you
put
onto
a
spring
the
more
it
which
is
is
a
measured
seem.
to
larger
variable
be.
determine
the
effect
of
will
changing
the
independent
stretch.
variable.
2
T
able
1.3.1
shows
the
data
from
an
investigation
into
3
resistance.
Plot
a
graph
using
this
T
o
make
the
T
able
effect
of
affects
0.0
0.1
0.2
that
only
altering
independent
1.3.1
Potential
sure
data.
0.3
0.4
0.5
the
the
variable
outcome
of
the
0.6
experiment,
other
factors
have
difference/V
to
Current/A
0.00
0.60
1.02
1.57
2.07
2.52
3.01
be
These
carefully
are
controlled.
control
variables.
7
1.4
Graphical
A
LEARNING
graph
can
be
analysed
to
analysis
find
the
relationship
between
the
two
OUTCOMES
variables.
At
the
end
should

plot
be
a
of
this
able
topic
you
to:
straight
Graphs
line
of
best
a
set
of
determine
straight

the
line
analyse
a
gradient
of
of
simple
a
the
graph
graph
best
relationship
two
to
between
If
the
a
line
the
data
not
ACTIVITY
collected
the
between
period
the
length
of
to
identify
the
lines
or
curves)
variables.
relationship
that
pass
These
through
lines
or
follow
close
to
of
and
of
graph
best
points
may
large
Y
ou
these
fit
with
appear
(Figure
an
not
fit
may
also
in
the
or
straight
Draw
pattern
the
above
of
line,
line
and
results.
uncertainties
made
results
a
number
errors
have
be
1.4.1).
equal
random
anomalous
to
mistakes
when
in
drawing
you
so
can
use
ruler
that
below
These
it
may
recording
the
line
of
passes
the
produced
a
line.
be
due
during
the
best
data.
Do
fit.
60
a
the
pendulum
or
use
50
the
data
T
able
provided
in
T
able
1.4.1.
1.4.1
2
Length/m
Period
l
T
2
/s
40
2
Δy
0.20
0.10
0.40
0.15
0.60
0.20
0.80
0.25
1.01
0.30
1.21
0.35
1.41
0.40
1.61
m/tnemecalpsiD
0.05
Point
to
Plot
a
graph
length
20
of
comparing
the
square
of
pendulum
the
Describe
the
in
(T
1
2
3
4
5
graph.
Figure
8
5.0 s
0
).
relationship
the
=
with
period
Time/s
shown
8.0 − 3.0
the
0

=
10
2
the
55.0 − 20.5
35.5 m
be
Δ x

=
=
checked
30
1.4.1
Drawing
a
line
of
best
fit
6
7
8
9
to
the
when
relationship
swing
the
use
a
points
experiment.
investigating
(straight
on
unexpectedly
pendulum’s
graphs
dependent
lines
points
draw
Some
you
onto
and
points.
through
data
drawn
the
variables.
the
are
independent
describe
to
Use
fit
the
shapes
Straight
the
relationships
points
between

linear
fit
Lines
through
showing
Gradients
The
gradient
between
To

find
the
the
Draw
a
read

Use
a
(for
the
can
be
used
to
find
a
mathematical
relationship
EXAM
two
are
triangle
the
points
widely
example,
in
It
right-angled
meets
that
change
line
variables.
gradient:
large,
triangle
points
of
two
to
on
the
spaced
points
find
x-value
triangle
the
line
and
that
lie
on
the
of
best
those
on
change
the
in
graph
fit.
whose
so
If
that
values
are
the
easily
it
y-value
(Δy)
and
the
grap
h
helps
.
join
the
a
to
draw
grap
h
‘insi
de’
select
gridlines).
the
easier
cur ve
d
the
possible,
is
TIP
from
cur ve
.
paper
Y
ou
grap
h
a
Ro ta
te
arou
nd
mus
t
as
a
if
neve
r
serie
s
of
do t-t
o-do ts
.
(Δx).
Δy

The
gradient
(m)
is
given
by
m
=
Δx
Intercepts
Sometimes
this
case
the
the
line
two
of
best
variables
fit
will
are
in
pass
directly
direct
through
proportion
the
to
origin.
each
In
other:
1
independent
If
the
as
line
linear
.
(c)
and
does
The
the
variable
not
line
∝
pass
will
through
cut
relationship
dependent
the
the
y-axis
origin
at
between
the
=
c
y
variable
a
the
point
relationship
known
variables
will
be
is
described
as
the
intercept
of
the
form:
x
y
mx
+
Figure
where
y
is
the
dependent
variable,
x
is
the
independent
variable,
m
1.4.2
You
can
pattern
the
gradient
and
c
is
the
intercept
on
the
sometimes
find
a
is
y-axis.
by
plotting
x
1
against
y
Graphs
showing
other
relationships
T
able
The
points
on
a
graph
may
also
follow
a
curve.
This
may
1.4.2
Examples
which
also
variables
represent
a
Instead
plotting
of
simple
mathematical
a
graph
relationship
comparing
the
x
between
and
y
the
variables
of
relationships
occur
in
between
physics
variables.
directly,
Relationship
Produces
line
1
a
graph
straight-
when
2
functions
such
as
plotting
y
or
may
show
the
relationship
more
clearly.
y
x
∝
y
x
plotted
against
y
x
plotted
against
y
x
plotted
against
2
2
x
∝
x
∝
y
1
1
y
SUMMARY
There
is
a
mathematical
illuminance
that
relationship
(brightness)
source.
Data
are
of
a
light
provided
in
between
source
T
able
and
the
the
light
distance
from
KEY
graphical
techniques
to
find
out
if
POINTS
1.4.3.
1
Use
y
QUESTION
this
relationship
is
A
to
1
illuminance
1
∝
or
illuminance
line
of
best
fit
is
used
either:
show
the
between
relationship
two
variables.
∝
2
distance
distance
2
A
straight
passing
T
able
line
of
through
best
the
fit
origin
1.4.3
shows
Distance/m
0.5
1.0
1.5
2.0
2.5
3.0
16.0
4.0
1.8
1.0
0.6
0.4
3
Curves
direct
can
proportionality.
also
show
–2
Illuminance/cd m
mathematical
relationships.
9
1.5
Vectors
There
LEARNING
At
the
end
should

be
of
this
the
between
two
classes
of
quantity
scalars
in
physics:
scalars
and
vectors.
OUTCOMES
able
describe
are
and
a
topic

A
scalar
quantity

A
vector
has
magnitude
(size)
but
no
direction.
you
quantity
has
magnitude
and
direction.
to:
difference
scalar
and
Comparing
a
a
scalar
and
a
vector
vector
Distance
and
displacement
are
both
lengths
which
can
be
measured
quantity
in

use
a
vector
diagram
the
resultant
of
two
to
metres:
find
vectors.

Distance
is
reference

a
scalar
to
the
Displacement
object
For
is
example,
walk
5
of
if
metres
distance
your
is
from
of
1.5.1
Vector
calculations
in
predicting
of
how
far
object
moves
without
walk
quantity.
(original
10
metres
towards
your
However,
It
is
a
measure
of
how
far
an
position).
northwards,
starting
your
point
turn
you
displacement
around
have
is
5
and
covered
metres
a
north
point.
quantities
such
as
mass
from
and
each
volume,
simply
add
together
or
are
other:
hurricanes.

Adding
a
mass
of
40 kg
to
a
mass
of
30 kg
3
WORKED
an
the
subtracted
paths
is
are
Scalars,
used
vector
origin
metres.
Combining
Figure
a
its
you
starting
It
direction.
back
15
quantity.
EXAMPLE
1

Removing
40 cm
gives
a
mass
of
70 kg.
3
of
water
from
100 cm
of
water
will
always
leave
3
60 cm
Find
the
resultant
of
the
acting
Figure
1.5.2.
on
the
ball
water.
three
Vectors,
forces
of
such
as
velocity
and
force,
cannot
be
simply
added
together.
in
To
find
the
resultant
of
vectors
you
must
also
take
their
direction
into
account.
5.2 N
6.1 N
Parallel
vectors
4.8 N
If
Figure
the
vectors
are
parallel
to
each
other,
then
you
can
add
or
subtract
1.5.2
to
Resultant
=
5.2 N
+
4.8 N
find
a
resultant.
Always
give
the
direction
of
the
resultant
in
your
−
answer.
6.1 N
=
3.9 N
to
the
right
Non-parallel
The
parallelogram
parallel
F
vectors
adjacent
R
2
to
vectors:
be
sides
added
by
of
(F
rule
and
parallelogram
allows
drawing
the
a
us
to
scale
).
The
find
(in
lengths
The
red)
of F
2
magnitude.
the
diagram
parallelogram
F
1
their
θ
the
rule
resultant
(Figure
(R)
of
the
and
F
are
two
vectors
the
in
by
1
Figure
10
1.5.3
The
parallelogram
rule
the
diagonal
of
the
parallelogram,
non-
T
wo
two
vectors
proportion
to
2
is
P
F
two
1.5.3).
represent
1
resultant
of
shown
in
green.
represented
WORKED
What
is
EXAMPLE
the
2
resultant
of
the
two
vectors
shown
in
Figure
1.5.4?
R
50 N
y
75 N
θ
Figure
1.5.4
x
Check
the
that
other
(Figure
the
two
vectors
sides
1.5.5).
of
are
drawn
the
Measure
to
the
same
parallelogram
the
length
and
and
scale.
the
angle
of
Then
draw
Figure
1.5.6
diagonal
the
diagonal,
SUMMARY
and
use
the
scale
factor
to
find
its
value
in
1
1
2
0
QUESTIONS
newtons.
Y
ou
follow
the
instructions
N
below
50 N
in
a
treasure
hunt.
15°
Calculate
the
total
distance
75 N
travelled
Figure
1.5.5
then
Vectors
at
right
angles
2
the
vectors
are
at
right
angles
to
each
other,
you
can
40 m
south
and
Draw
a
the
Where
and
theorem
and
trigonometry.
The
two
vectors
of
a
right-angled
triangle
with
the
resultant
can
be
of
found
the
triangle
(Figure
1.5.6).
The
size
of
forming
the
two
east.
to
find
velocity
use
acting
a
on
river,
a
as
boat
shown
in
the
Figure
hypotenuse
10 m
diagram
of
north,
70 m
form
crossing
sides
50 m
then
finally
scale
final
Walk
east,
resultant
vectors
Pythagoras’s
two
the
displacement:
1.5.7.
hypotenuse
using:
2
2
hypotenuse
=
adjacent
=
x
2
2
R
2
+
opposite
2
+
y
–1
The
angle
of
the
resultant
vector
can
be
found
5 m s
using:
–1
2 m s
opposite
tan θ
=
y
=
adjacent
x
y
–1
which
leads
to
the
relationship:
θ
=
tan
( )
x
Figure
WORKED
EXAMPLE
3
KEY
A
remote-controlled
followed
by
a
toy
is
movement
instructed
of
60 m
to
west.
move
What
80 m
the
toy
after
this
is
the
POINTS
south
displacement
1
of
Scalars
of
displacement:
2
R
R
2
=
=
have
80
can
2
+
60
√10 000
=
be
not
of
direction.
added
or
They
subtracted
simply.
2
=
but
10 000 m
100 m
2
Vectors
have
magnitude
Direction
magnitude
movement?
(size)
Magnitude
1.5.7
both
and
direction.
displacement:
Addition
of
vectors
has
60
–1
θ
=
tan
=
(
80
)
37°
to
take
into
direction
of
account
the
the
vectors.
11
1.6
Forces
Forces
LEARNING
acting
on
an
object
can
change
its
shape
or
the
way
it
is
OUTCOMES
moving.
At
the
end
should

be
of
this
able
describe
the
topic
you
to:
Describing
effects
of
simple
As
forces
acting
on
forces
are
find
the
vector
quantities
(they
have
size
and
direction)
they
are
objects
represented

forces
resultant
of
a
set
of
direction
of
in
diagrams
the
force
as
and
arrows.
the
The
length
direction
represents
of
the
the
arrow
size
of
gives
the
the
force.
forces
The

calculate
object
the
from
weight
its
gravitational
mass
field
of
unit
of
and
the
Example
When
are

se t
objects
When
or
TIP
ques
tions
=
on
the
the

weig
ht
Earth
10 N
kg
at
is
differe
nt
=
1.6 N
kg
two
you
ques
tion
air
surfaces
grip
be
touching
past
types
depending
against
objects
for
the
force
to
exist,
these
forces
forces
move
These
resistance
Floating
to
contact
movement.
each
each
other,
of
forces
are
on
where
they
forces
known
attempt
as
to
prevent
friction,
originate
from.
drag,
This
gives
other.
experience
upthrust
from
the
fluid
in
which
they
float.
Non-contact
o ther
forces
(e.g.
In
field
places
some
exist
situations
between
the
objects
are
not
in
direct
contact
but
forces
still
them.
g

Planets
are

Electrons
held
in
orbit
around
the
Sun
by
the
forces
of
gravity
−1
),
check
is
need
as
g
Moon
sure
(N).
Howe
ver
,
grav
itatio
nal
stren
gth
are
where
−1
.
newton
forces
objects
Most
the
forces
described
this
invo
lving
is
strength.
Contact
EXAM
force
an
so
mak
where
e
the
same
are
forces
bound
cause
to
atoms
attraction
by
electromagnetic
and
repulsion
in
forces.
The
magnets.
se t.

The
nucleus
of
Combining
The
an
force
is
is
held
together
by
strong
nuclear
forces.
forces
combination
resultant
atom
of
force.
all
In
of
the
many
forces
situations
acting
you
on
will
an
object
find
that
is
the
called
the
resultant
zero.
Weight
Weight
is
attraction
The
a
force
which
between
weight
of
the
the
acts
on
object
object
an
and
depends
object
the
on
because
of
the
gravitational
Earth.
two
factors:
the
mass
of
the
−1
object
and
the
gravitational
field
strength
(g
=
−1
W
12
(N)
=
m
(kg)
×
g
(N kg
)
10 N kg
on
Earth).
WORKED
Figure
EXAMPLE
1.6.1
shows
a
1
ACTIVITY
tug-of-war.
Which
team
is
winning?
Use
the
some
plasticine
effects

Stretch

Squash

Roll
it
then
of
it
to
explore
forces.
until
it
snaps.
it.
into
roll
a
ball
the
shape
ball
and
along
the
desk.
400 N
Figure
+
600 N
300 N
+
700 N

Throw

Rub
it
ball
against
along
the
the
desk
to
wall.
feel
1.6.1
the
Forces
to
the
left
Forces
to
the
right
=
400 N
=
+
300 N
600 N
+
=
700 N
1000 N
=
forces
are
balanced
so
the
Draw
1000 N
resultant
is
frictional
what
what
The
a
it
does
force
see
plasticine.
diagrams
to
explain
happens.
explore
magnets
EXAMPLE
and
the
zero.
Now
WORKED
force
to

2
the
have
Arrange
effects
on
them
each
so
that
bar
other.
they
repel
or
attract.
A
student
of
mass
45 kg
jumps
off
a
diving
board
into
a
deep
pool.

After
the
dive
the
student
then
floats
on
the
surface
of
the
Try
to
that
a
Calculate
the
weight
of
the
the
student.
Draw
W
=
balance
one
magnet
so
pool.
the
N-pole
N-pole
force
of
floats
the
above
other.
diagrams
for
these
mg
situations.
−1
=
b
Draw
he
a
falls
size
of
45 kg
diagram
and
as
these
×
10 N kg
showing
he
floats
forces
the
on
where
Air
=
450 N
forces
the
acting
surface
of
on
the
the
student
water.
Give
as
the
possible.
resistance
450 N
450 N
SUMMARY
QUESTIONS
1
landing
450 N
Figure
The
lunar
which
1.6.2
a
visited
mass
would
KEY
Earth
POINTS
of
module
Moon
15 000 kg.
this
and
the
weigh
on
the
on
had
What
the
Moon?
−1
(g
=
1.6 N kg
)
Moon
1
Forces
2
The
are
vector
quantities.
2
resultant
same
3
The
overall
weight
of
a
force
effect
of
an
of
is
the
object
is
a
single
other
the
force
forces
product
which
would
have
the
combined.
of
the
mass
and
If
the
lift
field
strength.
(W
=
largest
the
What
is
could
lift
mass
Earth
the
is
you
largest
when
could
150 kg.
mass
standing
you
on
the
the
gravitational
on
Moon?
mg)
13
1.7
Moments
The
LEARNING
turning
When
At
the
end
should

be
of
this
able
determine
force
effect
of
a
force
OUTCOMES
a
force
acts
on
an
object
it
may
cause
a
turning
effect,
known
as
you
the
moment
the
force
of
the
force.
This
turning
effect
depends
on
the
size
of
to:
the
acting
topic
moment
about
a
of
applied
and
the
distance
from
the
pivot
or
point
of
rotation.
a
fulcrum
Calculating
moments
The
of
(pivot)

combine
moments
resultant
moment
to
find
a
moment
perpendicular
a
M

analyse
to
find
systems
forces
in
and
is
(N m)
the
to
the
=
F
product
of
the
force
and
the
pivot:
(N)
×
d
(m)
equilibrium
distances.
Combining
When
WORKED
force
distance
EXAMPLE
1
there
moments
are
WORKED
several
forces
EXAMPLE
acting
a
resultant
moment
can
be
concrete
slab
found.
2
500 N
2.5 m
400 N
2.2 m
m
c
0
4
25 N
Pivot
Figure
1.7.1
Figure
A
long
nut
spanner
using
a
is
force
used
of
to
25 N.
turn
What
T
wo
is
the
moment
of
the
1.7.2
a
force
workers
1.7.2).
the
spanner
is
held
40 cm
using
large
lever
to
lift
up
a
(Figure
Worker
pivot.
A
applies
Worker
B
a
force
applies
a
of
force
400 N
of
at
500 N
a
distance
at
a
2.2 m
distance
from
2.5 m
nut?
from
M
(N m)
=
F
(N)
×
d
M
M
=
=
25 N
×
the
pivot.
What
moment
turning
effect
produced?
moment
=
(400
(worker
A)
+
moment
(worker
B)
×
2.2)
+
(500
×
2.5)
=
880
+
1250
10 N m
acting
Clockwise
and
2130 N m
against
each
other
can
be
subtracted
in
a
similar
way.
anticlockwise
Anticlockwise
When
describing
anticlockwise
1.7.3
total
0.4 m
Moments
Figure
the
=
=
Clockwise
is
(m)
Total
14
a
from
the
the
are
when
are
the
action
used
to
of
moments,
describe
the
the
terms
direction
of
clockwise
action
and
(Figure
1.7.3).
Moments
and
equilibrium
ACTIVITY
When
an
object
is
in
equilibrium
it
is
not
accelerating
or
rotating.
The
Test
two
equilibrium

There

The
is
no
conditions
resultant
clockwise
force
moment
the
principle
is
acting
equal
on
to
the
the
object.
anticlockwise
moment.
by
suspending
its
centre
centre
(a
second
of
these
points
is
called
the
principle
of
of
EXAMPLE
works
Try
Metre
400 N
from
through
best)
and
masses
various
masses
balanced
3
200 N
moments
ruler
the
then
on
either
moments
side.
WORKED
a
hole
suspending
The
of
are:
until
combinations
the
(Figure
ruler
is
1.7.5).
or
500 N
half-metre
0.4 m
0.6 m
ruler
d
d
Wire
d
1
loop
2
R
Slotted
Pivot
mass
hanger
Slotted
m
masses
m
1
2
Pivot
(nail
hole
centre
Figure
is
in
the
distance
equilibrium
d
of
the
(Figure
third
child
from
the
pivot
if
the
a
seesaw
in
there
is
no
Calculate
1.7.4).
each
clockwise
overall
resultant
two
moments
=
anticlockwise
the
side
the
facts
the
acting
weights
can
be
used
and
to
find
pivot
the
distance
point.
the
values
of
the
force
R
should
find
that
the
ruler
and
only
balanced
when
the
d
upwards
R
The
moments
using
masses
the
clockwise
The
of
moments.
is
distance
principle
force
You
These
the
equilibrium:
from

Testing
moments
of

1.7.5
seesaw
on
For
through
ruler)
1.7.4
Figure
Find
of
force
=
moments
Clockwise
(0.6 m
R
400 N
are
+
also
moments
×
must
equal
200 N
the
+
sum
500 N
of
=
the
downward
forces:
the
are
equal
to
moments.
1100 N
balanced.
=
anticlockwise
500 N)
=
(0.4 m
300 N m
=
160 N m
×
moments
400 N)
+
+
(d
×
200 N)
200d N m
KEY
200d
moments
anticlockwise
=
300
–
POINTS
160
1
A
force
can
cause
a
turning
140
d
=
=
effect
0.7 m
(moment).
200
2
SUMMARY
QUESTIONS
What
are
the
two
conditions
required
for
an
object
to
be
moment
of
product
the
perpendicular
the
An
pivot.
object
is
of
a
the
to
3
1
The
(M
in
force
the
is
force
and
distance
=
Fd)
equilibrium
in
when
the
clockwise
equilibrium?
moments
2
Three
people
4.0 m.
the
Sketch
three
of
a
equal
weight
diagram
people
could
sit
on
showing
sit
so
that
a
the
the
seesaw
of
possible
seesaw
total
length
positions
would
be
where
balanced.
are
anticlockwise
there
is
no
equal
to
the
moments
overall
and
resultant
force.
15
1.8
Stability
Objects
LEARNING
are
attracted
At
the
end
should

find
be
the
of
this
able
topic
each
you
to:
centre
of
gravity
for
of
the
of
billions
and
seems
gravitational
of
forces
call
this
to
pull
particles
separately
the
come
weight
from
a
of
we
of
the
each
of
which
use
the
single
a
Earth.
Instead
single
equivalent
object
point
as
in
a
of
is
whole.
the
considering
resultant
This
object.
This
single
is
called
a
centre
of
gravity
objects
compare
objects
the
these
force
The

of
by
force
the
range
composed
OUTCOMES
the
using
centre
of
stability
the
centre
of
gravity
is
the
point
from
which
the
weight
appears
to
act.
of
position
of
Finding
gravity.
As
the
will
the
weight
always
directly
This
of
be
in
above
idea
(Figure
can
centre
an
object
gravity
acts
equilibrium
the
be
1.8.1).
of
centre
used
A
to
lamina
of
when
it
the
is
centre
of
gravity
suspended
from
an
a
object
point
gravity.
find
is
from
a
the
thin
centre
sheet
of
of
gravity
for
material
in
a
lamina
any
shape.
ACTIVITY

Second
Make
near
point
several
the
Suspend
it
can
small
edges
the
of
holes
the
lamina
rotate
freely.
lamina.
so
that
When
it
Stand
comes
to
gravity
is
rest
the
directly
centre
below
of
the
First
point
point
of
suspension.
Centre
Card
WORKED
of
EXAMPLE
of
gravity
suspension.
draw
Why
do
carry
a
some
very
tightrope
long
flexible
walkers
Plumbline
pole
lowers
and
of
be
pole
lower
held
centre
increases
the
and
can
their
that
(a
mass
string
on
with
the
end)
through
it
The
of

ends
downwards
centre
small
plumbline.
gravity
stability.
bend
the
so
of
line
Repeat
at
Figure
1.8.1
Finding
gravity
gravity
the
of
a
centre
of
least
and
line
centre
process
two
a
the
pencil
point
following
(This
the
the
Use
from
suspension
pole?
a
The
a
more
the
must
of
to
of
pass
gravity.)
using
points
of
suspension.
triangular

The
point
where
the
lines
meet
lamina
even
further
(Figue
1.8.2).
is
Three-dimensional
Three-dimensional
They
draw
can
lines
where
you
diagonal
Figure
1.8.2
A
tightrope
be
and
would
lines
objects
are
suspended
see
the
where
expect
joining
middle
of
centre
of
gravity.
objects
they
for
the
a
little
from
a
more
a
meet.
The
regularly
corners
uniform
difficult
number
of
a
of
cube
ruler).
to
points
centre
shaped
walker
sphere,
16
also
the
of
gravity
objects
meet,
investigate.
but
the
(e.g.
it’s
is
hard
where
centre
to
usually
of
a
the
Stability
An
of
object
standing
gravity
above
is
the
beyond
on
directly
base.
the
If
base
the
it
a
table
above
object
will
will
the
be
point
is
topple
tilted
gravity
gravity
An
object
when
if
that
can
released
tilting
the
the
is
centre
be
said
object
the
centre
of
of
gravity
be
results
and
in
in
is
acts,
gravity
i.e.
moves
of
Pivot
the
return
stable
the
centre
gravity
outside
will
its
force
Centre
Pivot
tilted
to
when
reaction
Centre
of
If
the
1.8.3c).
of
Pivot
1.8.3
equilibrium
and
(Figure
Centre
Figure
in
where
base
to
of
its
the
original
equilibrium.
centre
of
object
gravity
This
being
it
will
topple.
position
occurs
moved
upwards.
If
the
object
falls
over
with
a
slight
push
then
the
object
was
in
Figure
unstable
lowers
equilibrium.
and
so
the
This
object
happens
falls
into
a
when
the
position
centre
where
it
is
of
1.8.4
During
gravity
more
feet
stable.
of
and
these
them
Designing
A
stable
car
has
for
object
a
wide
a
judo
competitors
match
spread
bend
down.
actions
more
the
their
Both
make
stable.
stability
has
a
low
centre
wheelbase
and
of
low
gravity
centre
and
of
a
wide
gravity
to
base.
make
A
it
racing
more
ACTIVITY
stable
when
gravity
it
might
travels
topple
around
corners.
A
car
with
a
higher
centre
of
Balance
over.
a
flat
they
fall
SUMMARY
or
Why
only
2
does
fill
a
the
Describe
Which
and
chest
top
how
laboratory
3
of
range
can
over.
be
tilted
You
can
objects
see
how
before
tilt
the
on
far
they
of
drawers
become
more
unstable
if
is
you
could
objects
in
gently
by
pushing
tilting
the
object
surface
the
side
itself.
you
find
the
centre
of
gravity
for
a
KEY
in
Figure
unstable
1.8.5
is
in
stable
equilibrium
1
equilibrium?
POINTS
The
centre
object
the
is
2
3
The
of
the
weight
appears
to
centre
of
object
from
its
at
an
which
object
gravity
suspending
of
centre
the
of
act.
by
Stability
gravity
point
of
found
depends
1.8.5
from
drawers?
stool.
the
which
Figure
of
and
QUESTIONS
by
1
a
surface
different
an
on
of
can
be
the
points.
object
the
position
of
gravity.
17
1.9
Investigating
Hooke’s
law
Extension
LEARNING
OUTCOMES
The
At
the
end
of
this
topic
increase
called
should
be
able
describe
the
to
its
original
the
force
acting
on
and
the
its
compare
spring
the
caused
force
is
by
a
stretching
removed
the
force
spring
is
may
shape
and
size.
17th
century,
the
Robert
Hooke
found
that
there
was
a
simple
between
the
extension
of
the
spring
and
the
force
acting
extension
it.
of
The
different
a
extension
on

of
When
a
relationship
spring
length
extension.
relationship
In
between
the
to:
return

in
you
extension
of
a
spring
is
proportional
to
the
force
acting
on
it.
springs.
Expressed
mathematically
F
where
the
force
is
F
is
the
spring
effectively
a
to
spring
a
is
is
a
the
extension
spring
the
of
stiff
is:
kx
The
measure
law
spring
the
and
k
constant
by
one
stiffness
of
is
a
constant
represents
metre.
a
the
The
spring.
A
known
size
spring
high
of
as
the
constant
spring
spring.
EXAMPLE
loaded
20 cm
What
is
stretch
indicates
WORKED
from
x
constant.
required
constant
A
force,
=
Hooke’s
to
the
with
a
5.0 kg
mass
and
its
length
increases
45 cm.
spring
F
=
k
=
constant
of
this
spring?
kx
–1
F
5.0 kg
×
10 N kg
50 N
–1
=
=
x
b
How
long
is
0.45 m
the
spring
if
–
a
0.20 m
load
of
=
200 N m
0.25 m
7.0 kg
is
applied?
–1
F
Figure
x
1.9.1
=
7.0 kg
×
10 N kg
=
=
0.35 m
–1
k
The
spring
0.2 m,
EXAM
Mak
e
sure
Hook
e’s’
the
law
that
the
Limit
you
limita
tions
law
as
well
as
of
Hooke’s
new
by
length
is
0.35 m
from
its
original
length
of
0.55 m.
proportionality
law
only
applies
proportionality.
If
the
up
until
load
is
a
point
increased
called
after
the
this
limit
point
of
the
spring
itself
.
will
continue
proportion
18
the
extended
TIP
remem
ber
to
so
has
200 N m
to
to
extend
the
force
but
this
applied.
additional
extension
will
not
be
in
Elastic
If
the
limit
spring
is
stretched
even
further
then
it
will
become
permanently
Beyond
This
deformation
called
The
the
limit
is
of
elastic
happens
elastic
graph
force
means
in
will
when
1.9.2
The
Up
the
return
spring
to
shows
spring
proportionality).
limit).
not
to
is
its
original
stretched
length.
beyond
a
This
point
limit
Figure
applied.
it
this
It
the
follows
extension
Hooke’s
continues
point
the
to
of
law
stretch
spring
is
a
up
up
able
to
spring
to
to
when
point
point
return
P
E
to
a
m m/noisnetxE
deformed.
elastic
Elastic
if
the
force
is
removed.
Beyond
the
elastic
limit
the
(the
Increasing
the
permanently
force
(the
its
0
original
spring
force/N
will
Figure
be
limit
P
Stretching
length
limit
E
1.9.2
Stretching
a
spring
deformed.
ACTIVITY:
FINDING
Investigate
a
spring

Suspend
a
spring

Measure
and

Add
a

Add
more

Calculate

Remove
small
THE
using
from
record
mass
masses
the
its
and
SPRING
the
a
technique
stand
at
extension
as
described
shown
in
here.
Figure
1.9.3.
length.
record
one
CONSTANT
a
mm
the
time,
for
each
new
length.
recording
the
Spiral
length
each
spring
10
time.
length.
20
Pointer
is
the
followed
loaded
may
masses
during
beyond
be
one
by
one
unloading.
the
elastic
If
limit
to
check
not,
and
that
then
the
the
the
last
same
spring
few
data
pattern
was
30
Slotted
Plot
a
graph
and
find
of
the
load
(x-axis)
against
total
extension
scale
(y-axis)
Load
50

The
the
gradient
gradient
of
this
using
graph
a
line
of
best
or
stretching
force
fit.
is:
Figure
1.9.3
Investigating
extension
Δy
masses
40
invalid.
mm

Hanger
points
Hooke’s
law
=
load
Δx
1
and
so
the
spring
constant
is
given
by
k
=
gradient

Investigate
the
extension
of
a
rubber
band
using
the
same
process.

To
what
Hooke’s
extent
do
the
spring
and
the
rubber
band
obey
law?
SUMMARY
QUESTIONS
KEY
1
1
Calculate
the
length
of
a
spring
of
original
length
50 cm
constant
40 N m
Hooke’s
the
when
a
mass
of
2.0 kg
is
Use
the
data
in
T
able
1.9.1
to
determine
the
spring
a
that
spring
proportional
on
it.
(F
to
=
the
load
kx)
constant.
2
T
able
of
it.
acting
2
states
extension
suspended
is
from
law
and
−1
spring
POINTS
The
spring
constant
for
a
1.9.1
spring
to
Force
applied/N
0
1
2
3
0
3.2
6.4
9.6
4
5
12.8
16.0
the
produce
force
unit
required
extension.
6
3
Length/cm
is
Stiffer
springs
have
a
larger
19.2
spring
constant.
19
Section
SECTION
1
What
1:
SI
1
Practice
units
are
Practice
exam
used
for
questions
the
exam
questions
1
following
4
Find
the
resultants
quantities?
using
a
Mass
a
16 km
east
b
Time
b
27 km
west
c
Length
d
Speed
e
Density
f
The
g
Pressure
5
The
Pythagoras’
mass
and
meteorite
of
a
of
these
and
20 km
and
50 km
of
measured
Calculate
south
the
Complete
this
table
measurements
a
and
standard
small
sample
shown
density
in
of
of
the
the
sample.
force
of
with
north
as
cm
2
displacements
theorem.
volume
are
diagrams.
moment
1
descriptions
the
3
cm
3
25
25
20
20
15
15
10
10
5
5
of
appropriate
prefixes
forms.
Description
Using
SI
prefixes
standard
unit
and
…….kN
5
…….nm
7.2
form
3
a
force
of
5000
×
10
g
N
newton
on
−7
a
length
seven
of
×
10
m
hundred
6
and
An
expedition
to
the
planet
Mars
is
being
twenty
planned.
The
landing
module
has
a
mass
of
nanometres
50 000 kg.
a
current
of
30
…….mA
a
Draw
a
labelled
force
diagram
showing
milliampere
this
990 μg
module
Mars.
resting
Include
the
on
size
the
of
surface
the
of
forces.
−1
(g
=
3.7 N kg
)
Mars
3
Use
a
these
scale
diagram
combinations
to
of
find
the
forces.
resultant
of
b
The
closest
and
Earth
spacecraft
a
days
how
approach
is
56
can
fast
between
million
only
must
carry
it
Mars
kilometres.
supplies
travel
in
If
the
for
order
600
to
30 N
to
Mars
run
50 N
b
20 N
40 N
40°
c
20 N
40 N
30°
2
5
N
20
and
out?
back
before
these
supplies
get
7
On
a
iron
building
girders.
site
To
a
crane
is
counteract
used
the
to
lift
turning
heavy
9
effect
A
group
the
of
students
stretching
of
a
were
spring
asked
and
to
investigate
elastic
band.
3
a
concrete
mounted
position
2.0 m
on
of
and
balance
block,
the
this
of
other
block
10.0 m
loads
mass
of
2.0
side
can
from
of
be
the
different
×
10
the
kg,
crane.
adjusted
pivot
is
in
They
The
and
between
order
measured
then
recording
to
shown
in
the
the
extension
elastic
the
the
by
of
loading
extension,
the
spring
masses
producing
and
the
results
table.
sizes.
Load/N
Spring
Elastic
length/cm
length/cm
3
The
mass
lifting
a
b
of
cable
the
is
girder
is
connected
Where
should
the
placed
for
crane
the
What
is
while
staying
always
the
the
has
in
×
10
3.0 m
concrete
largest
to
4.2
to
be
load
from
block
in
the
equilibrium
be
kg
connected
and
the
the
pivot.
0
5.5
8.0
1
6.2
8.9
2
6.9
10.4
3
7.6
12.2
4
8.3
14
5
9.0
15.8
6
9.7
17.6
7
10.4
19.4
8
11.1
20.9
9
11.8
22.2
be
equilibrium?
crane
if
the
can
lift
load
3.0 m
from
pivot?
3
2.0 × 10
3.0 m
kg
Pivot
a
Plot
a
suitable
comparison
graph
of
the
allowing
extensions
the
of
the
spring
3
4.2 × 10
kg
and
b
During
the
to
c
8
Describe
how
to
find
the
centre
of
gravity
the
elastic.
which
elastic
the
part
band
of
the
extension
stretching
was
proportionally
load?
Determine
the
spring
constant
for
the
of
spring.
an
irregularly
shaped
metal
sheet
of
uniform
10
A
single
spring
was
used
to
suspend
a
block
thickness.
of
a
mass
40 kg.
What
is
The
the
spring
spring
extended
constant
for
by
0.5 m.
this
spring?
b
How
so
can
that
two
the
combination
i
twice
ii
half
identical
spring
be
for
arranged
the
is:
that
that
springs
constant
of
of
a
a
single
single
spring
spring?
21
1.10
Moving
objects
and
displacement–time
graphs
Key
LEARNING
At
the
end
should
be
of
this
able
topic
Displacements
you
define
in
key
definitions
describing
and
distances
to:
The

definitions
OUTCOMES
the
(starting
used
motion
displacement
point)
in
of
a
an
object
stated
is
the
distance
it
is
from
the
origin
direction.
of
The
total
distance
an
object
travels
is
not
always
the
same
as
the
objects

describe
object
the
by
motion
of
interpreting
displacement–time
an
a
displacement,
as
the
pendulum
motion.
during
one
1.10.1
Units
and
motion
the
minute
object
but
may
move
swinging
its
backwards
will
travel
displacement
will
symbols
used
and
forwards
never
be
very
during
distance
large.
The
speed
of
an
The
average
object
speed
is
for
the
a
distance
whole
it
covers
journey
(or
in
part
a
particular
of
that
time.
journey)
is
in
given
equations
Unit
or
considerable
velocity
by:
distance
Quantity
a
graph.
Speed
T
able
A
x
Symbol
average
speed
=
or
v
=
time
distance
m
x
displacement
m
s
t
−1
The
SI
unit
of
speed
is
the
metre
per
second
(m s
)
but
kilometres
per
−1
hour
time
s
(km h
)
and
miles
per
hour
are
also
used.
t
At
different
points
an
object
may
be
travelling
faster
or
more
−1
speed
m s
v
or
c
slowly
than
average.
The
speed
at
any
particular
time
is
called
the
−1
velocity
m s
v
or
u
instantaneous
speed
−2
acceleration
m s
a
The
velocity
of
an
object
is
Displacement–time
Displacement–time
from
the
origin
over
the
in
a
particular
direction.
graphs
graphs
a
speed
period
represent
of
time.
the
The
distance
time
is
of
an
plotted
object
on
the
100
horizontal
axis
The
in
graph
m/tnemecalpsiD
the
sprinters
the
blue
while
Figure
are
sprinter
the
displacement
1.10.1
from
took
the
can
be
starting
longer
than
is
used
line
the
plotted
to
at
the
determine
any
red
on
time.
sprinter
It
to
vertical
how
also
far
axis.
away
shows
reach
the
that
100 m
50
finishing
The
line.
velocity
can
be
found
from
the
gradient
of
a
displacement–time
graph:
change
Δs
velocity
0
0
5
=
displacement
change
Δt
10
in
=
in
time
Time/s
Figure
1.10.1
The
displacement
sprinters
during
a
of
two
WORKED
EXAMPLE
race
What
is
the
velocity
of
the
red
sprinter
as
shown
in
100 m
Δs
–1
Velocity
(m s
)
–1
=
=
Δt
22
Figure
=
10 s
10 m s
1.10.1?
More
complex
represented
as
changes
journeys,
by
a
graph
involving
(Figure
in
the
gradient:
steeper
the
gradient

The

A
zero

A
negative
gradient
towards
(flat
gradient
the
the
line)
changes
1.10.2).
greater
indicates
(downward
starting
in
velocity,
These
the
zero
slope)
can
changes
be
will
be
shown
velocity.
velocity.
will
indicate
movement
back
point.
300
D
250
C
SUMMARY
QUESTIONS
m/tnemecalpsiD
200
B
1
Calculate
blue
the
sprinter
velocity
in
of
Figure
the
1.10.1
150
A
and
the
and
C
taxi
of
during
Figure
parts
A
1.10.2.
100
2
Sketch
50
a
more
displacement
a
sprinter
speeding
0
0
100
200
300
the
race
realistic
graph
showing
up
at
and
the
then
for
him
start
of
slowing
Time/s
down
Figure
1.10.2
The
graph
analysed
T
able
1.10.2
Journey
shows
to
Describing
part
give
the
the
During
0–60 s
moving
B
The
the
at
taxi
journey
of
of
a
the
first
a
taxi
through
shown
in
a
T
able
town.
It
can
seconds
of
the
the
taxi
taxi
is
The
speed.
60
How
line
that
seconds.
the
on
the
From
graph
the
and
60 s
120–240 s
This
taxi
moves
speed
is
at
a
steady
slower
than
speed
for
again.
part
A
of
The
the
journey.
D
Finally,
so
to
has
means
the
taxi
stops
again.
The
240–300 s
the
the
slope
but
graph
a
line
120 s
The
taxi
of
is
the
taxi
on
has
the
this
has
passed
the
line.
movement
slopes
the
is
upwards
not
line
is
showing
increasing.
line
on
displacement
shallower
the
taxi
shows
displacement
horizontal.
The
he
finish
1.10.2.
60–120 s
C
after
100 m
be
taxi
sixty
for
a
movement
steady
stops
of
information
motion
Description
A
the
the
is
graph
not
is
changing
moving.
on
the
slope
than
travelling
graph
is
graph
for
more
is
upwards
part
A.
This
slowly.
horizontal
again
and
so
stopped.
KEY
POINTS
Acceleration
1
When
is
an
object
unrealistic
would
as
changes
it
accelerate
shows
for
velocity
instant
several
it
accelerates.
changes
seconds
in
and,
The
velocity
.
instead
graph
In
of
reality
a
sharp
above
the
taxi
change,
graph
would
show
a
curve
as
the
speed
displacement–time
shows
the
object
over
Similarly
the
sprinters
would
accelerate
from
the
The
starting
they
reached
a
top
speed
and
then
slow
after
the
period
of
of
an
time.
velocity
finishing
found
of
from
an
object
the
can
gradient
of
blocks
a
until
a
graph
changed
be
gradually
.
movement
the
2
displacement–time
A
displacement–time
graph.
line.
23
1.11
Acceleration
and
velocity–time
graphs
Acceleration
LEARNING
OUTCOMES
The
At
the
end
of
this
topic
acceleration
of
an
object
is
the
rate
of
change
of
velocity:
you
–1
should
be
able
change
to:
in
velocity
(m s
)
describe
object
the
by
motion

find
the
object

find
an
the
where
a
using
of
a
–
u
=
(s)
t
is
the
which
initial
the
velocity,
object
v
is
the
changed
final
velocity
and
t
is
the
time
velocity.
an
travelled
the
u
during
graph
distance
object
v
or
an
graph
acceleration
using
the
of
interpreting
velocity–time
)
=
time

(m s
–2
acceleration
WORKED
EXAMPLE
1
A
accelerates
by
−1
rally
car
to
25 m s
from
a
standing
start
in
15 s.
graph.
What
is
Noting
the
acceleration
that
the
initial
of
the
velocity
car?
is
0
gives:
–1
–1
Velocity/m s
v
–
u
(25
–
0) m s
–2
a
=
=
=
1.7 m s
30
t
25
X
X
X
Y
15 s
X
20
X
X
Velocity–time
15
graphs
X
X
10
A
X
second
way
to
represent
the
motion
of
an
object
is
through
a
X
5
0
velocity–time
X
graph.
On
these
graphs:
X
X
0
2
4
6
8
10

the
time
is
represented

the
velocity
on
the
x-axis
Time/s
Figure
1.11.1
A
simple
is
represented
on
the
y-axis.
velocity–time
Figure
1.11.1
compares
the
movements
of
two
cars.
Car
X
accelerates
graph
uniformly
seconds
–1
from
but
0
then
to
10
seconds.
reaches
a
Car
steady
Y
accelerates
speed.
It
is
for
the
important
first
to
six
notice
Velocity/m s
−1
that
car
Y
does
not
stop.
It
keeps
travelling
at
18 m s
until
the
end
6
of
B
X
5
the
test.
X
4
Using
velocity–time
graphs
to
find
acceleration
3
A
C
The
2
1
0
acceleration
can
be
found
from
the
gradient
of
a
velocity–time
graph:
X
Time/s
X
X
change
Δv
E
D
–1
acceleration
=
in
velocity
=
X
change
Δt
in
time
–2
–3
WORKED
Figure
1.11.2
Motion
phase
of
A
a
the
toy.
toy
In
phase
B
is
is
at
a
constant
the
acceleration
of
car
X
throughout
the
test,
shown
in
the
Figure
toy
2
is
What
accelerating.
EXAMPLE
During
1.11.1?
velocity.
–1
During
phase
C
the
v
toy
–
u
(25
–
0) m s
–2
a
decelerates.
Phase
D
=
=
=
10 s
t
that
with
is
the
a
toy
is
now
negative
moving
moving
velocity;
backwards
it
and
As
accelerating.
phase
comes
24
E
the
to
Finally,
toy
rest.
2.5 m s
shows
with
displacement–time
graphs,
velocity–time
during
slows
and
several
phases
of
motion
(Figure
1.11.2).
graphs
can
show
EXAM
Using
an
velocity–time
graphs
to
find
the
distance
travelled
by
T
ake
TIP
care
no t
to
confus
e
object
the
You
can
area
find
the
beneath
broken
the
line
into
shapes
WORKED
The
the
down
simple
distance
on
a
simple
cannot
be
EXAMPLE
simple
travelled
of
a
an
velocity–time
shapes
used
and
the
object
graph.
the
area
area
may
by
measuring
This
area
can
calculated.
be
the
be
Where
differe
nt
grap
hs.
T
hey
simila
r
but
differe
nt
motion
may
they
look
repres
ent
quan
tities
estimated.
3
velocity–time
motion
by
two
robot.
graph
What
in
Figure
distance
1.11.3
does
it
–1
represents
Velocity/m s
travel?
4.5
The
graph
is
broken
down
into
three
simple
shapes:
4.0
triangle
A,
rectangle
B
and
triangle
C.
3.5
The
areas
are
calculated:
3.0
1
Area
A
=
1
×
base
×
height
=
2
×
5
×
4
2.5
=10
2
2.0
Area
B
=
Area
C
=
base
×
height
=
10
×
4
=40
1.5
1
×
6
×
4
=12
2
1.0
The
total
area
is
10
+
40
+12
which
represents
a
distance
0.5
travelled
of
62 m.
Time/s
0
0
Figure
5
10
15
20
25
1.11.3
ACTIVITY

Attach
ticker
vibrating
regular

Let
the
pin
tape
or
intervals
object
to
pen
an
object.
which
(usually
fall,
Thread
produces
50
allowing
dots
a
per
a
the
dot
tape
on
through
the
paper
a
at
second).
pattern
of
dots
SUMMARY
to
be
made
on
1
the
Calculate
the
acceleration
of
strip.
the

QUESTIONS
This
pattern
reveals
the
distance
the
object
has
travelled
graph
th
of
a
second
and
so
the
velocity
and
in
each
part
of
the
in
1
each
toy
acceleration
in
Figure
1.11.2.
can
50
be
2
calculated.
a
Calculate
distance
toy
Ticker
Object
in
the
total
travelled
Figure
by
the
1.11.2.
timer
b
released
What
is
the
final
5
displacement
of
the
toy?
Speed
4
KEY
POINTS
Clamp
to
hold
base
of
Ticker
1
tape
stand
The
acceleration
can
be
found
of
from
an
object
the
5
3
4
gradient
of
a
velocity–time
3
2
graph.
1
0
0
2
Time
2
Soft
The
distance
travelled
by
an
pad
1
Ticker
tape
object
can
be
found
using
Go
with
dots
the
Figure
1.11.4
Investigating
falling
using
a
ticker
tape
timer
area
under
velocity–time
the
line
of
a
graph.
25
1.12
Newton’s
laws
of
motion
The
LEARNING
Greek
keep
At
the
end
should
be
of
this
able
topic
the
you
on
to:
is

state
and
scientist
apply
an
object
faster
his
an
the
laws
of
observation
of
in
If
TIP
his
and
does
is
as
the
force
was
be
moving
object
on
it.
(v
tends
∝
to
However,
The
required
F).
greater
He
come
based
to
Aristotle
rest
the
to
this
force
idea
unless
performed
there
no
his
idea
Galileo,
and
the
when,
idea
hundreds
was
found
to
of
years
be
later,
wrong.
tests
Isaac
there
mean
girl
are
fo rces
that
no
ideas
called
about
the
laws
forces
of
and
movement.
Some
motion.
motion
resultant
force
acting
on
an
object
it
will
remain
at
velocity.
object
will
remain
continue
unmoving)
to
Roll
a
in
straight
a
on
to
move
in
a
straight
line
at
constant
speed
change
unless
acted
behaviour
is
on
by
called
a
resultant
force.
This
inertia
it.
marble
Note
along
line
that
a
smooth
unless
it
desk
and
encounters
frictional
forces
are
you
will
see
something
acting
and
that
that
these
it
continues
produces
will
slow
a
force
the
there
marble
fo rce.
alwa
ys
the
of
our
are
first
objec
ts,
and
developed
law.
o ppos
ite
fo rces
(Figur
e
a
velocity.
ge t
the
third
e
differe
nt
the
is
reluctance
resul
tant
paire
d
on
to
abou
t
and
no t
The
no t
becaus
no
by
discoveries
law
there
(or
confus
ed
equa
l
an
acting
verify
out
fully
key
constant
caref
ul
Just
would
that
force
to
carried
First
law
that
constant
situations.
of
Be
thought
a
a
Newton
EXAM
at
Newton’s
motion
were
range
moving
object
obvious
experiments
three
Aristotle
OUTCOMES
down.
T
he
This
act
such
first
cause
law
an
leads
object
to
to
the
idea
that
it
is
always
resultant
forces
which
accelerate.
chair
1.12
.2a).
Second
The
law
of
acceleration
acting
on
the
of
motion
an
object
object
and
is
proportional
inversely
to
proportional
the
to
resultant
the
mass
force
of
the
object.
This
statement
leads
to
the
force
=
mathematical
mass
×
relationship:
acceleration
or
F
=
ma
−2
When
force
mass
is
is
called
WORKED
expressed
the
in
newton
EXAMPLE
kg
(N)
and
in
acceleration
honour
of
in
m s
Newton s
the
unit
of
work
1
7
A
cruise
ship
of
mass
1.5
×
10
kg
is
pushed
by
an
engine
4
force
of
2.3
×
10
N.
The
water
resistance
acting
on
the
ship
4
1.2
×
10
N.
What
is
the
acceleration
of
the
ship?
4
The
resultant
force
acting
on
the
ship
is
(2.3
−
1.2)
×
4
=
1.1
×
10
N.
4
F
1.1
×
10
N
–4
Figure
1.12.1
The
acceleration
of
a
ship
a
=
=
=
7
depends
the
26
on
its
resultant
mass
force.
and
m
1.5
×
10
kg
7.3
×
10
–2
m s
10
N
is
Third
law
of
motion
a
Reaction
When
an
equally

sized
When
chair.
in

an
The
object
sit
Sun
wobble
detect
the
your
force
a
chair
force
(Figure
an
the
equally
B
then
on
B
exerts
force
an
A.
acts
force
object
downwards
equal
to
your
on
the
weight
but
1.12.2a).
Earth
sized
These
planets
weight
reaction
(Figure
on
object
direction
your
a
1.12.2b).
large
on
opposite
produces
exerts
some
a
direction
exerts
also
in
on
chair
upwards
Earth
exerts
force
you
The
A
which
force
stellar
orbiting
keeps
on
the
wobbles
other
it
in
Sun
orbit,
causing
have
been
but
it
the
to
used
to
stars.
Rockets
Weight
Gases
they
from
burning
expand.
downwards
These
and
fuel
hot
the
are
expelled
gases
rocket
gain
gains
from
the
base
momentum
an
equal
as
and
of
a
they
rocket
are
opposite
as
b
pushed
momentum
Sun
upwards.
Earth
As
the
fuel
is
used
and
leaves
the
rocket,
its
mass
decreases
and
the
F
Figure
acceleration
of
the
rocket
will
increase
as
a
(
WORKED
EXAMPLE
1.12.2
Examples
of
the
third
law
=
m
)
in
action
2
5
At
launch,
The
a
the
rocket
What
is
produces
the
Remember
the
thrust
The
initial
the
minus
of
a
of
of
resultant
the
the
a
rocket
maximum
acceleration
that
weight
mass
and
force
the
of
rocket
force
=
mg
=
is
×
10
kg.
acting
launch?
on
the
rocket
will
be
weight.
rocket
7.80
is
given
by:
×
−1
10
kg
×
10 N kg
6
=
7.80
6
F
7.80
13.5 MN.
at
5
W
fuel
13.5
×
10
×
10
N
6
N
–
7.80
×
10
N
–2
a
=
=
=
7.3 m s
5
m
7.80
×
10
kg
5
b
One
fuel
of
minute
but
the
still
into
the
flight
produces
rocket
at
this
the
the
rocket
same
has
thrust.
used
What
is
1.0
×
the
10
kg
of
acceleration
stage?
Figure
1.12.3
An
is
Now
use
the
reduced
mass
of
the
rocket
to
find
the
Ariane
used
6
13.5
×
10
rocket
launch
system
satellites
acceleration:
from
F
to
French
Guiana.
6
N
–
6.80
×
10
N
–2
a
=
=
=
9.9 m s
5
m
6.80
×
10
kg
KEY
1
SUMMARY
POINTS
The
first
shows
forces
1
Draw
a
law
of
motion
QUESTIONS
diagram
showing
a
ladder
leaning
against
a
wall,
that
are
resultant
needed
to
cause
so
acceleration.
that
the
someone
ladder,
can
wall
climb
and
up
it.
Draw
all
of
the
forces
acting
on
2
floor.
The
second
shows
2
A
skydiver
just
of
before
1000 N
mass
60 kg
opening
just
after.
her
experiences
parachute
Calculate
the
two
instants.
(g
and
air
an
=10 N kg
)
resistance
air
acceleration
−1
these
an
of
resistance
of
the
that
law
F
=
of
motion
ma
400 N
3
of
skydiver
at
The
third
shows
in
law
that
equal
of
motion
forces
and
always
opposite
act
pairs.
27
1.13
Momentum
and
impulse
Momentum
LEARNING
OUTCOMES
Momentum
At
the
end
of
this
topic
an
should
be
able

the
is
a
vector
related
to
the
mass
and
velocity
of
object.
to:
p
state
quantity
you
law
of
=
mv
conservation
−1.
of

linear
use
of
the
An
momentum
law
of
momentum
analysis
of
after
of
units
shows
that
the
units
of
momentum
are
kg m s
conservation
to
find
the
WORKED
velocity
the
objects
before
EXAMPLE
1
and
impacts.
What
is
the
momentum
of
a
minibus
of
mass
2000 kg
when
−1
moving
at
5.0 m s
?
–1
p
=
mv
=
2000 kg
×
4
5.0 m s
=
1.0
×
10
–1
kg m s
Impulse
As
you
saw
change
the
change
in
force
and
which
it
in
the
previous
velocity
and
momentum
this
caused
impulse
is
units
means
resultant
the
by
the
a
force
product
forces
are
momentum
of
is
called
the
required
of
an
the
force
to
object.
impulse
and
the
time
The
of
the
for
acts:
impulse
The
topic,
therefore
for
that
impulse
the
=
are
units
of
Ft
=
N s.
change
As
this
impulse
in
is
and
a
momentum
change
of
momentum
momentum
are
this
identical:
–1
kg m s
The
symbol
≡
means
Conservation
As
A
the
acts
Ft
Momentum
momentum
the
size
is
impulse
on
both
on
it
then,
from
object
change
to’.
an
object
can
only
be
changed
when
a
force
an
must
an
interaction
Newton’s
object
by
third
changes
an
between
equal
two
law,
then
and
you
the
can
opposite
objects
A
see
that
momentum
and
of
when
the
another
amount.
B
the
forces
acting
conserved
is
the
objects.
the
two
objects
must
be
of
the
same
size
and
last
for
the
same
same
amount
Ft
and
of
the
quantities
This
In
gives
any
This
used
time.
This
impulse
of
the
law
means
the
to
means
on
B
is
momentum
interaction
law
exactly
28
identical
momentum
of
of
on
as
of
momentum
In
1.13.1
‘is
N s
B
Ft
Figure
≡
as
given
but
in
the
by
total
the
the
of
momentum
situations
where
−Ft.
of
amount
amount
impulse
The
opposite
conservation
the
that
same
analyse
of
that
two
objects
momentum
before
A
is
given
gain
(Figure
by
equal
1.13.1).
momentum:
momentum
two
object
directions
linear
of
on
the
objects
is
after
conserved.
any
collision.
collide
collision
This
with
law
each
is
can
other
.
be
Investigating
To
investigate
used
(Figure
timer
T
o
or
carry
needs
by
law
1.13.2).
the
be
of
measurements
T
o
is
of
successfully
do
this
a
movement
of
movement
experiment
reduced.
and
conservation
Their
ultrasonic
out
to
the
momentum
momentum,
monitored
their
the
trolley
is
trolleys
using
a
can
ticker
be
tape
position.
effect
placed
of
frictional
on
a
ramp
forces
and
the
ACTIVITY
ramp
is
tilted
spaced
and
dots.
the
trolleys
so
This
friction
can
that
be
a
ticker
shows
forces
varied
that
have
by
tape
the
trolley
been
placing
attached
is
to
the
moving
compensated.
additional
trolley
at
The
blocks
has
equally
constant
masses
of
metal
velocity
of
the
onto
Use
a
ramp
collect
them.
data
collisions
to
and
for
timer
Tape
Pin
of
that
so
results
the
The
1.13.2
first
partway
or
a
The
pin
trolley
down
and
is
a
ramp
be
to
Trolley
used
to
compensate
allowed
The
make
can
B
and
ramp.
data
of
can
pushed
the
movement
WORKED
ramp
cork
conservation
In
A
trolleys
them
then
stick
be
law
of
momentum.
will
to
have
each
analysed
to
(at
rest
frictional
collide
may
to
for
A
with
demonstrate
discuss
the
is
sources
exact
of
error
.
initially)
forces.
a
Velcro
other
not
relationship
experimental
Figure
the
to
of
Cork
Y
our
Trolley
range
verify
conservation
Ticker
trolleys
a
second
strips,
after
confirm
the
the
trolley
magnets
collision.
law
of
momentum.
EXAMPLE
2
experiment
a
trolley
of
mass
0.5 kg
is
pushed
at
a
WORKED
EXAMPLE
Why
running
does
3
into
a
wall
−1
velocity
mass
of
0.3 m s
1.0 kg
and
.
It
sticks
collides
to
it.
with
The
a
second
resulting
stationary
trolley
pair
trolley
moves
of
hurt
more
than
walking
into
it?
off
The
change
of
momentum
−1
with
a
velocity
of
0.1 m s
.
Has
momentum
been
conserved?
will
Find
the
momentum
before
the
collision:
=
mv
=
0.5 kg
×
0.3 m s
time
–1
=
the
momentum
after
the
collision
faster
will
also
remembering
that
that
have
a
combined
mass
of
–1
=
mv
=
1.5 kg
×
shows
always
that
momentum
0.1 m s
shorter.
This
force
in
momentum
=
)
time
–1
=
0.15 kg m s
conserved
in
the
collision
(as
be
much
larger.
it
is).
SUMMARY
QUESTIONS
1
complete
Copy
T
able
was
are
impact
the
will
This
you
the
1.5 kg.
(F
p
be
the
change
trolleys
when
and
0.15 kg m s
means
Find
greater
moving
–1
p
be
and
T
able
1.13.1
by
finding
the
missing
values.
KEY
POINTS
1.13.1
1
−1
Object
cricket
Mass/kg
ball
Velocity/m s
0.16
Momentum
of
the
of
an
mass
is
the
and
product
the
velocity
−1
Momentum/kg m s
object.
(p
=
mv)
20
2
Momentum
is
a
vector
is
conserved
6
meteorite
5000
6.5
×
10
quantity.
3
2
A
car
is
pushed
using
a
constant
force
of
500 N
for
5
Momentum
all
How
much
momentum
does
the
car
in
seconds.
interactions.
gain?
29
1.14
More
The
LEARNING
concept
the
end
should
be
of
this
able
topic
rocket
you
collide
apply
of
the
energy
law
to
of
be
applied
each
other
to
situations
and
also
to
where
explosions
and
a
collisions
range
including
of
collision
both
objects
could
be
moving.
This
is
often
the
case
collisions
a
traffic
collision.
The
objects
may
not
stick
together
in
a
collision,
explosions
instead

can
off
conservation
in
and
bounce
to:
During
situations
momentum
and
propulsion.
More

of
momentum
OUTCOMES
objects
At
about
apply
the
rocket
laws
of
motion
they
can
rebound
and
separate
after
the
impact.
to
systems.
WORKED
EXAMPLE
In
of
a
a
game
match
ball.
the
billiards/pool,
white
Initially
1
the
cue
balls
balls
ball
are
of
mass
0.20 kg
collides
head
on
moving
in
are
with
opposite
the
used.
During
object
directions.
The
cue
−1
ball
has
velocity
of
0.30 m s
and
the
object
ball
has
velocity
−1
−0.10 m s
.
After
the
collision
the
cue
ball
continues
to
move
in
−1
its
is
original
the
direction
velocity
of
but
the
at
a
object
reduced
ball
after
velocity
the
of
0.05 m s
.
What
collision?
Before:
−1
−1
0.30 m s
−0.10 m s
After:
−1
0.05 m s
Figure
1.14.1
Choose
the
direction
ball
and
Find
?
the
cue
as
ball
direction
negative.
object
initial
as
positive,
Subscripts
t,
c
and
and
o
the
opposite
identify
the
total,
total
momentum
of
the
balls:
)
(0.20 kg
–1
p
=
p
t
+
p
c
cue
ball.
=
(0.20 kg
×
0.3 m s
–1
+
×
–0.1 m s
)
o
–1
=
Find
the
0.04 kg m s
momentum
of
the
cue
ball
after
–1
Figure
1.14.2
When
billiard
balls
collide
p
=
0.20 kg
×
0.05 m s
the
collision:
–1
=
0.01 kg m s
c
they
don’t
stick
together.
The
They
often
move
off
total
momentum
momentum
different
after
the
collision
is
the
same
as
the
with
before
and
so
the
momentum
of
the
object
ball
velocities.
−1
must
be
Finally
0.04
find
−
the
0.01
=
velocity
0.03 kg m s
of
the
object
ball:
–1
p
0.03 kg m s
o
v
=
–1
=
=
0.15 m s
o
m
0.20 kg
o
As
the
answer
moving
30
in
the
is
positive,
same
this
direction
means
as
the
that
cue
the
ball.
object
ball
is
now
Explosions
The
law
of
conservation
momentum
following

T
wo
The
The
track
of
(Figure
held
are
initial
When
the
gliders
the
This
placed
on
together
released
momentum
end
of
and
opposite
track
are
at
of
applies
can
in
a
be
the
even
when
the
demonstrated
centre
cushion
This
(explosion)
Further
experiments
masses
and
the
same
and
means
is
with
they
still
can
measuring
a
of
small
will
system
released
the
velocities
momentum.
release
are
gliders
are

of
the
they
The
momentum
zero.
in
initial
the
of
air
a
linear
and
so
air
track.
eliminates
friction.
when

is
1.14.3).
gliders
floats
the
of
system
gliders
that

way
a
identical
most

of
they
time
be
is
zero
will
the
as
move
showing
therefore
that
spring
forced
total
their
apart
that
equal
between
apart
them
the
velocity
and
they
and
by
opposite
momentum
is
reach
have
so
spring.
zero.
the
equal
amounts
after
the
zero.
be
the
carried
out
velocities
– v
using
after
gliders
the
of
different
explosion.
+v
Air
track
Gliders
Figure
Similar
1.14.3
Using
experiments
a
linear
can
air
be
track
to
carried
investigate
out
explosions
using
two
trolleys
on
a
track.
KEY
POINT
Recoil
1
When
by
a
gun
rapidly
the
same
time
momentum.
WORKED
A
rifle
is
fired
the
expanding
of
the
It
bullet
gases.
gun
must
therefore
EXAMPLE
mass
is
The
propelled
bullet
gain
moves
an
has
equal
backwards
forwards
gained
and
at
high
opposite
of
and
a
bullet
of
can
of
be
of
applied
pairs
of
explosions.
(recoils).
SUMMARY
fi res
conservation
collisions
objects
of
2
4.5 kg
to
At
amount
law
momentum
velocity
momentum.
The
mass
10 g
forwards
with
QUESTIONS
a
1
A
satellite
has
a
mass
of
−1
velocity
of
300 m s
.
What
is
the
recoil
velocity
of
the
rifle?
500 kg.
Use
a
subscript
b
to
identify
the
bullet
and
r
for
the
it
rifle.
ejects
To
adjust
50 kg
of
its
speed
fuel
at
−1.
40 m s
Find
the
momentum
of
the
in
–1
p
=
m
b
v
b
The
rifle
=
0.01 kg
×
300 m s
momentum
gain
the
the
change
same
change
in
3.0 kg m s
speed
also
is
and
–1
=
b
must
What
bullet:
momentum
but
in
the
of
the
satellite?
opposite
2
If
the
1
is
fuel
1
minute
ejected
in
Question
direction.
ejected
over
a
period
of
–1
p
–3.0 kg m s
r
v
=
–1
=
=
–0.67 m s
what
is
the
average
r
m
4.5 kg
r
force
acting
on
the
satellite?
31
Section
SECTION
1
The
1:
1
Practice
Practice
exam
displacement–time
questions
graph
shows
exam
questions
2
2
the
4
During
an
experiment
a
trolley
of
mass
4.0 kg
−1
height
a
of
Find
a
skydiver
the
during
velocity
of
the
a
dive.
skydiver
moves
with
with
stationary
and
Find
the
of
trolley
0.5 m s
of
.
mass
It
collides
3.0 kg
and
two
trolleys
stick
together
moving
off
at
a
50 s.
new
b
velocity
between
the
20 s
a
a
velocity
of
the
skydiver
velocity.
What
is
the
velocity
of
the
trolley
between
combination?
50 s
and
100 s.
5
During
a
docking
manoeuvre
a
supply
pod
Height/km
of
mass
4000 kg
International
2.0
accidently
Space
collides
Station
(mass
with
the
100 000 kg)
−1
with
the
1.5
a
relative
pod
change
6
During
to
pot
velocity
attaches
in
a
game
the
to
velocity
of
final
of
the
of
2.0 m s
station
the
space
snooker
black.
a
The
.
Assuming
what
is
the
station?
player
white
attempts
ball
strikes
1.0
−1
the
stationary
and
the
black
black
ball
with
is
a
velocity
propelled
of
1.2 m s
forwards
−1
with
0.5
a
velocity
Assuming
calculate
0
Time/s
0
10
20
30
40
50
60
70
80
90
the
of
that
the
1.0 m s
both
after
balls
velocity
of
have
the
the
impact.
equal
white
mass,
ball
after
impact.
100
7
A
billiard
ball
of
mass
0.3 kg
hits
a
cushion
−1
with
2
A
car
takes
8 s
to
−1
15 m s
slow
down
from
a
speed
5 m s
the
as
it
approaches
a
velocity
of
2.5 m s
.
It
rebounds
off
of
−1
to
a
cushion
in
the
opposite
direction
with
a
junction.
−1
velocity
a
What
b
If
is
the
acceleration
of
the
a
the
car
has
a
mass
of
of
−2.4 m s
car?
800 kg,
what
is
What
is
billiard
braking
force
required
to
slow
the
During
take-off
10 000 kg
can
a
jet
aeroplane
produce
a
of
40 kN.
At
the
point
of
maximum
take-off
What
mass
momentum
of
the
is
the
final
momentum
of
the
billiard
ball?
thrust
8
of
initial
ball?
car?
b
3
the
the
the
An
artillery
gun
of
mass
1500 kg
fires
a
shell
plane
−1
of
experiences
a
drag
force
of
Calculate
the
initial
10 kg
at
a
velocity
of
400 m s
acceleration
of
the
recoil
velocity
of
the
gun?
the
plane.
–1
400 m s
b
Calculate
the
the
of
point
acceleration
of
the
plane
at
10 kg
take-off.
1500 kg
32
.
20 kN.
is
a
mass
What
9
A
group
of
students
conservation
X
and
Y
.
of
Trolley
investigated
momentum
X
was
the
using
allowed
to
law
two
roll
of
a
trolleys,
along
and
accelerated
before
moving
along
adjusted
trolley
to
both
then
counteract
trolleys
to
collided
continue
with
frictional
to
trolley
move
Y
acceleration
the
of
trolley
X
as
it
ramp?
What
distance
did
trolley
X
travel
before
a
impact
with
trolley
Y?
forces.
The
The
the
down
a
the
ramp
is
travels
b
ramp
What
mass
of
trolley
X
was
0.5 kg.
causing
c
forwards
Calculate
before
separately.
d
the
and
Calculate
momentum
just
the
after
mass
the
of
of
trolley
X
just
impact.
trolley
Y
.
X
The
graph
trolleys
between
the
two
trolleys
lasts
for
0.25 s.
e
The
impact
Y
Ramp
shows
during
an
the
motion
of
the
What
Y
two
is
the
during
average
the
force
acting
on
trolley
impact?
investigation.
–1
Velocity/m s
Trolley
X
Trolley
Y
2.5
2.0
1.5
1.0
0.5
0
0
1
2
3
4
5
6
Time/s
33
1.15
Energy
and
energy
transformations
The
LEARNING
concept
due
At
the
end
of
this
topic
to
a
be
able
define

describe

energy
transfers
and
transformations
calculate
(energy
acting
to
energy
energy
the
or
is
fundamental
transformation
of
to
physics.
All
events
occur
energy.
is
defined
as
the
capacity
to
do
work,
for
example
when
a
to:
force

energy
transfer
you
Energy
should
of
OUTCOMES
work
through
a
by
All
(and
joule
often
a
an
object
mechanical
energy
One
done
transferred)
as
moves
of
through
a
distance.
This
is
sometimes
referred
work.
work
energy
done)
is
is
quite
measured
a
small
a
unit
called
quantity
in
and
so
the
joule
kilojoule
(kJ)
(J).
is
used.
force
distance.
The
forms
Energy
is
in
T
able
in
form
T
able
of
sometimes
1.15.1,
of
to
energy
1.15.1
Energy
energy
referred
help
is
us
referred
Forms
of
form
to
as
being
describe
to
as
the
a
in
different
transfer
of
forms,
energy.
as
A
shown
change
transformation
energy
Description
thermal
This
refers
to
the
heat
energy
stored
within
an
object.
light
Light
carry
is
an
without
sound
Sound
the
Kinetic
potential
energy
from
need
energy
vibrating
kinetic
electromagnetic
energy
is
object
for
the
particles
energy
Potential
place
is
energy
due
to
its
in
the
is
a
to
wave
place
associated
sound
energy
the
it
can
quickly
medium.
energy
a
and
very
of
energy
position
with
the
wave.
a
moving
stored
(being
off
in
object.
an
the
ACTIVITY
ground),
being
Think
about
electrical
are
so
the
a
range
devices
useful
energy
to
why
they
electrical
as
take
you
can,
in
as
including
energy
spring
state.
an
circuits
electric
transfer
energy
through
wires
current.
This
energy
is
stored
in
the
nucleus
of
atoms.
radios,
transfers
involving
electric
energy
see
electrical
2.9,
2.10
energy
and
see
4.5,
and
for
transfers
2.11.
motors
Energy
that
energy.
you
identify
transfer
and
transformation
any
The
ideas
explain
34
a
bulbs.
sure
wasted
chemical
as
telephones,
microphones,
Make
or
(such
many
thermal
light
Electrical
in
For
and
stretched)
state
transformations
place
televisions,
energy
Describe
nuclear
that
physical
of
and
us.
its
of
how
energy
devices
transfer
and
operate.
transformation
can
be
used
to
of
Examples:

When
you
chemicals
energy

When

and
you
stored
into
walk
in
in
heat
kinetic
into
a
light,
the
the
sound,
energy
as
(Figure
When
as
potential
transferred
catapult
elastic.
energy
the
is
energy
transform
heat,
potential
stairs
body
stretch
the
Fireworks
up
your
to
fire
you
a
stone,
release
stone
kinetic
flies
up
it
in
potential
the
energy
outwards
energy
energy
shoot
stored
gravitational
the
potential
1.15.1).
potential
they
energy
into
(Figure
stored
and
into
the
even
air
energy
is
in
is
transformed
1.15.2).
their
chemicals
gravitational
(Figure
1.15.3).
Figure
Wasted
1.15.1
Chemical
potential
energy
your
in
gravitational
In
any
energy
transformed
more
useful
become
transfer
into
that
a
force
work
given
by
work
done
This
out
transformation
to
energy
energy
the
which
has
not
some
of
cannot
the
be
disappeared.
surroundings
or
energy
used
It
to
has
energy
is
do
or
W
WORKED
will
and
been
=
moves
done
force
=
just
dissipated
by
an
the
object
force.
through
The
a
distance
amount
×
distance
moved
in
the
of
we
work
say
done
is
direction
of
the
force
Figure
1.15.2
Elastic
Fd
=
Fd
=
a
motorcycle
flat
80 N
road
has
using
a
to
be
force
pushed
of
80 N.
to
a
garage
How
much
of
energy
→
the
kinetic
stone
2.5 km
work
×
2.5
×
10
5
m
=
2.0
×
10
J
QUESTIONS
Figure
Describe
the
energy
transformations
involved
1.15.3
Chemical
using
a
battery-operated
torch
charging
a
mobile
c
boiling
kettle.
heat
sound
+
b
potential
energy
in:
→
a
potential
elastic
done?
SUMMARY
1
the
energy
3
W
energy
EXAMPLE
along
be
heat
relationship:
broken-down
away
+
any
in
A
→
potential
work
acts
has
the
or
thermal
work.
spread
Mechanical
When
cells
energy
+
+
light
kinetic
gravitational
+
energy
potential
phone
energy
a
KEY
2
Copy
and
and
complete
distances
for
T
able
1.15.2
mechanical
comparing
work
done,
work.
1
T
able
POINTS
force
Scientists
in
1.15.2
terms
describe
of
energy
transformation
a
Work
done
b
c
5.0 kJ
4.3 J
40 N
A
mechanical
energy
2000 N
and
Distance
60 m
and
energy
transfer.
2
Force
events
is
this
transfer
called
is
work
found
of
done
using
the
20 cm
equation
W
=
Fd
35
1.16
Energy
sources
for
electricity
Electricity
LEARNING
over
At
the
end
should

be
of
this
able
describe
is
an
important
topic
light,
you
for
to:
how
very
large
kinetic
distances
energy
electricity
or
which
is
to
resources
generate
can
be
state
of
some
energy
as
met
transform
it
There
by
is
using
a
a
it
is
simple
into
to
other
transfer
constantly
wide
range
forms
increasing
of
energy
such
as
demand
sources.
energy
sources
electricity
advantages
disadvantages
alternative
heat.
to
used
Non-renewable

and
alternative
Non-renewable
energy
form
OUTCOMES
of
and
and
so
are
in
energy
limited
sources
supply
or
are
have
fuels
that
limited
cannot
be
replaced
lifespans.
using
energy
resources.
Fossil
Fossil
of
fuels
fuels
plants
include
and
coal,
animals
oil
that
and
natural
died
gas,
millions
of
formed
years
from
the
remains
ago.
ACTIVITY
These
Research
and
the
use
renewable
Caribbean
of
fossil
energy
and
write
a
in
fuels
large
fuels
amounts
pressure
the
about
what
should
to
reduce
the
fossil
fossil
spin
energy.
turbines
producing
The
heat
which
waste
is
drive
used
gases
to
and
produce
electricity
high
generators.
of
can
produce
carbon
very
dioxide
are
large
amounts
released
of
leading
energy
to
but
global
dependency
Oil
this
Sulfur
is
causes
the
most
accounting
SUMMARY
dioxide
acid
is
also
released,
especially
from
burning
coal,
rain.
significant
for
more
energy
than
90%
source
of
the
used
total
in
the
Caribbean,
electricity
production.
QUESTION
Nuclear
Which
energy
require
a
power
sources:
A
a
furnace
fuels.
and
1
a
thermal
to
fuels
quantities
warming.
on
of
steam
in
be
vast
done
burnt
short
Burning
report
are
large
amount
nuclear
power
station
produces
heat
using
nuclear
fuels
such
as
of
uranium.
These
fuels
are
not
burnt
but
release
thermal
energy
inside
a
land?
reactor
b
damage
c
are
the
core
can
be
used
on
a
near
to
where
electricity
power
is
fairly
plants
cheap
electricity.
very
to
are
very
operate.
However,
dangerous
a
process
called
nuclear
fission.
expensive
They
can
to
build
produce
and
very
dismantle
large
but
quantities
and
they
also
requires
produce
safe
radioactive
storage
for
waste
thousands
which
of
years.
required?
Accidents
are
contaminate
No
nuclear
very
large
power
rare
but
areas
the
of
stations
escaping
radioactive
material
can
land.
operate
in
the
Caribbean
and
none
are
POINTS
currently
Large-scale
production
fossil
fuel
power
There
station
electricity
takes
place
burning
or
in
nuclear
had
in
planned.
in
been
the
built.
are
a
range
of
energy
other
Renewable
can
a
can
started
construction
abandoned
find
the
additional
of
project
detail
a
nuclear
before
about
power
the
reactor
nuclear
reactions
smaller
energy
sources
sources
produce
energy
sources
produce
electricity
without
being
used
electricity
up.
on
You
but
5.4.
Renewable
which
Cuba
1980s
plants.
renewable
The
sources
are
either
quickly
replaceable
or
have
effectively
scale.
unlimited
36
through
the
is
2
split
small
of
scale
1
nuclei
unreliable?
are
KEY
the
atmosphere?
Nuclear
d
when
lifespans.
Several
examples
are
shown
in
T
able
1.16.1.
T
able
1.16.1
Energy
Solar
A
source
power
summary
of
some
Example
There
are
no
large-scale
cells)
power
the
plants
many
buildings
panels
Most
solar
Caribbean
Key
No
sunlight
converted
to
advantages
fuel
Plenty
in
the
required.
of
sunlight
Caribbean.
Electricity
using
can
produced
semiconductor
building
cells.
it
is
to
on
in
be
be
Water
has
is
trapped
dams
a
10%
dam
used
electricity
No
behind
and
to
as
allowed
fuel
Can
flows
used
Wind
turbines
The
but
electricity
battery
storage
required.
Quite
expensive
to
build.
used.
it
of
required.
which
amounts
electricity
Water
very
quickly.
drives
on
fuel
required.
Predictable
and
a
energy
output.
amounts
precious
small-
and
systems
Caribbean
No
in
large
is
of
land
resource
islands.
Only
scale
to
is
estuaries
not
Floods
few
trapped
are
large
There
islands
valleys
are
estuaries
medium-
can
very
in
be
used
as
there
or
few
the
on
are
rivers.
suitable
Caribbean
islands.
turbines.
Alters
habitats
and
wildlife.
currently.
Wigton
farm
on
wind
Jamaica
produces
of
around
provide
energy
so
the
produce
large
drive
turbines
is
Caribbean
could
produce
night
which
escape.
the
at
heaters
needs.
Tidal
Can’t
in
Dominican
providing
power
disadvantages
roofs.
Republic
Tidal
Key
have
water
the
the
operates
electricity
installed.
twenty
it
in
energy
from
is
sources
directly
new
homes
their
The
of
in
have
Barbados
on
The
solar
Caribbean
but
energy
How
(photovoltaic
Hydroelectricity
renewable
20 MW
electricity.
The
wind
turbine
spins
blades
mounted
on
towers.
No
fuel
Plenty
required.
of
around
wind
island
Offshore
tourism
Some
turbines
by
noise
systems.
produced
Large-scale
large
wind
or
could
spoiling
pollution
especially
wind
affect
views.
is
from
farms.
farms
small-scale
local
generation
possible.
Geothermal
Beneath
energy
volcanic
of
St
Kitts
Nevis
vast
the
islands
and
there
geothermal
Research
are
are
reserves
of
energy.
projects
underway
develop
a
to
power
station.
Biofuels
Sugar
islands
could
on
produce
crude
is
many
and
be
ethanol
energy
No
released
by
is
pollution
caused
radioactive
sources
decay
reliable.
the
within
Earth
used
to
water
Only
and
are
a
very
few
locations
are
suitable.
very
is
heat
into
steam
and
steam
drives
the
turbines.
cane
grown
Thermal
some
used
oils
to
oil.
to
or
replace
Biological
New
material,
be
as
wood,
sugar
or
such
ethanol,
is
The
not
add
extra
carbon
to
land
crops
to
Does
dioxide
can
fairly
quickly.
cane,
burnt.
supplies
grown
used
may
grow
be
food
to
grow
better
for
fuel
used
increasing
populations.
the
atmosphere.
37
1.17
Potential
kinetic
Potential
LEARNING
energy
the
end
should
be
of
this
able
topic
masses
you
force
to:
the

calculate
and
energy
can
arise
because
an
object
is
stretched
or
OUTCOMES
compressed.
At
energy
the
kinetic
energy
the
change
to
When
the
acted
you
spring
through
investigated
and
a
the
force
distance
Hooke’s
caused
and
law
the
therefore
in
1.9
spring
did
to
work
you
added
stretch.
in
This
stretching
spring.
of
objects
Gravitational

calculate
gravitational
in
a
range
potential
of
potential
energy
An
object
that
potential
situations.
in
its
can
fall
energy.
gravitational
change
in
due
When
to
it
potential
potential
the
pull
changes
of
its
gravity
height
has
gravitational
then
there
is
a
change
energy:
gravitational
gravitational
=
EXAM
energy
in
mass
change
×
energy
×
field
strength
in
height
TIP
or
ΔE
=
mgΔh
p
T
he
trans
positio
n
the
kine
tic
equa
tion
most
of
This
equation
is
probab
ly
diffi
cult
one
need
strugg
le
the
equation
for
mechanical
work
done.
the
you
WORKED
will
matches
energ
y
to
do.
then
If
EXAMPLE
1
you
mem
orise
How
much
energy
is
required
to
500 kg
the
sand
alter
nate
show
n
on
lift
version
s
these
page
500 kg
20 m
(Figure
will
work
be
to
a
height
of
1.17.1)?
2
ΔE
done
equal
potential
EXAMPLE
sand
s.
The
WORKED
of
lifting
to
the
energy
=
mgΔh
=
500 kg
the
sand
gravitational
gained:
20 m
p
–1
a
A
fast
bowler
can
bowl
×
10 N kg
×
20 m
a
5
=
cricket
ball
of
mass
160 g
1.0
×
10
J
at
−1
40 m s
.
How
much
kinetic
sand
energy
1
E
=
does
this
ball
have?
2
mv
Figure
1.17.1
Gaining
gravitational
2
k
potential
1
=
–1
×
0.16 kg
×
(40 m s
energy
2
)
2
=
b
128 J
What
is
the
speed
of
powerboat
of
mass
it
of
kinetic
a
600 kg
if
Kinetic
has
40 kJ
The
The
rearrangement
of
energy
energy?
kinetic
movement.
kinetic
energy
energy
of
an
object
is
the
energy
equation
The
relationship
1
kinetic
×
E
2
×
with
its
is:
gives:
energy
=
3
2
associated
the
40
×
10
1
2
×
mass
×
speed
or
2
E
=
k
J
2
mv
2
k
v
=
=
√
√
m
600 kg
As
you
more
–1
=
38
11.5 m s
can
see
kinetic
an
object
energy
than
with
a
a
large
small,
mass
slow
and
moving
high
speed
object.
will
have
Transposition
of
the
equation
WORKED
To
find
v
if
given
the
mass
and
the
kinetic
energy,
you
need
the
equation.
Here
is
the
coconut
1
Original
of
mass
0.5 kg
falls
process.
25 m

3
to
A
rearrange
EXAMPLE
equation:
E
=
a
tree.
How
fast
will
2
mv
it
2
k
from
be
travelling
when
it
reaches
2

Multiply
both
sides
by
2:
2E
=
mv
=
v
the
ground?
k
2E
Find
k

Divide
both
sides
by
the
gravitational
potential
2
m:
energy
m
ΔE
2E
lost:
=
mgΔh
=
0.5 kg
=
125 J
p
k

T
ake
the
square
root
of
both
=
sides:
v
–1
m
Transfer
between
E
and
is
common.
It
of
k
gravitational
happens
every
10 N kg
×
25 m
E
p
Transformation
×
Use
potential
time
energy
something
to
falls.
kinetic
The
energy
to
the
find
kinetic
the
equations
2
energy
equation
speed:
×
E
2
×
125 J
k
v
for
kinetic
energy
and
potential
energy
can
be
used
to
calculate
=
=
the
√
m
speed
of
the
falling
object,
assuming
there
is
negligible
air
0.5 kg
resistance.
–1
=
Oscillations
A
pendulum
gravitational
side
there
and
back
is
of
a
pendulum
serves
as
an
potential
a
transfer
again.
22.4 m s
The
example
energy.
of
As
of
the
the
gravitational
quantities
of
transfer
pendulum
potential
energy
between
swings
energy
involved
can
kinetic
from
to
be
and
side
kinetic
to
energy
calculated
SUMMARY
using
the
equations
in
the
worked
example
for
the
falling
1
Calculate
mass
falling
A
EXAMPLE
pendulum
3 cm
above
freely.
bob
its
What
is
of
4
25 m.
mass
60 g
equilibrium
the
is
displaced
position
maximum
speed
and
of
sideways
then
the
so
allowed
that
to
it
is
2
An
a
the
gravitational
potential
energy
the
bob
loses
as
it
of
a
when
you
jet
loaded
It
from
notice?
aircraft
mass
can
12 km
1.0 kg
2.0 kg
ground
do
A380
fully
550 000 kg.
bob?
a
reach
the
What
height
Find
will
to
speeds
then
Airbus
has
swing
the
and
coconut
WORKED
QUESTIONS
coconut.
of
travel
with
a
at
a
speed
swings
−1.
of
to
the
equilibrium
250 m s
position:
a
–1
ΔE
=
mgΔh
=
0.06 kg
×
10 N kg
How
much
does
it
How
much
kinetic
energy
–2
×
0.03 m
=
1.8
×
10
J
p
When
the
pendulum
reaches
the
central
position
all
of
this
b
potential
energy
will
be
lost,
matched
by
a
gain
in
have?
kinetic
potential
and
the
speed
can
be
calculated
(Figure
gravitational
energy
energy
does
it
1.17.2).
have?
2
×
E
k
v
=
m
–2
2
×
1.8
×
10
J
=
Maximum
Maximum
gravitational
gravitational
potential
potential
energy
energy
KEY
0.06 kg
POINTS
–1
=
0.77 m s
1
The
change
potential
ΔE
=
of
gravitational
energy
is
given
by
mgΔh
p
2
Figure
1.17.2
Energy
changes
Maximum
The
kinetic
energy
of
an
kinetic
1
in
a
pendulum
swing
energy
object
is
given
by
E
=
k
2
mv
2
39
1.18
Conservation
The
LEARNING
At
the
should
end
be
most
important
rule
about
energy
of
is
the
energy
law
of
conservation
of
OUTCOMES
of
this
able
topic
energy
which
states:
Energy
cannot
you
be
created
or
destroyed.
It
can
only
be
transferred
or
to:
transformed.

state
and
apply
the
law
of
This
conservation

provide
of
rule
allows
examples
the
is
dissipated
surroundings
reducing
energy
the
analyse
and
explain
a
wide
variety
of
systems.
as
for
energy
loss
to
the
surroundings
into
There
heat
amount
available
to
where
Spotting
energy
us
energy
is
always
a
loss
transformations,
of
though
future
but
transfers.
no
energy
longer
Dropping
If
you
of
energy
usually
is
as
heat.
disappearing
useful
for
to
the
This
when
doing
surroundings
means
in
fact
that
the
it
in
energy
often
energy
is
looks
still
as
present
work.
objects
pick
up
gravitational
a
wooden
potential
block
energy
and
will
drop
it
onto
transform
to
the
ground
kinetic
the
energy
as
the
Gravitational
block
falls
but
transformed
sound
the
Kinetic
(Figure
surroundings
similar
kicks
and
on
energy
the
block
thermal
will
energy
1.18.1).
and
stop.
Even
becomes
The
warming
the
original
up
the
sound
energy
block
energy
has
and
been
some
dissipates
into
heat.
energy
A
Heat
then
into
sound
process
the
ball
warm
up
rest
lost
is
as
happens
gains
some
to
the
and
of
when
loses
the
you
kinetic
energy
kick
a
football.
energy.
turns
into
Over
heat
With
time
within
repeated
the
ball
the
will
ball.
The
surroundings.
impact
Pendulums
When
Figure
1.18.1
Energy
is
dissipated
the
the
a
pendulum
swing
will
decrease.
over
Some
a
of
period
the
of
energy
time,
is
the
leaving
height
the
of
system.
surroundings.
There
the
two
frictional
bob.
air
are
The
rubs
to
and
Eventually
losses.
need
As
force
the
be
time.
these
is
stand.
it
of
this
provided
masses
energy
are
air
the
the
will
This
it
also
will
of
the
loss.
the
kinetic
As
forces.
pendulum
motion
of
pendulum
frictional
swinging
to
a
loss
keep
system
downwards
to
the
this
frictional
force
as
energy
the
wire
the
of
is
wire
the
energy.
energy
provided
small
energy
to
to
random
where
reduces
stop
gradual
energy
into
point
a
leading
experiences
kinetic
be
heat
attached
move
is
At
into
with
happening
the
transformed
there
pendulum
Masses
potential
reduce
energy).
stand
the
Because
to
will
transfers
the
through
energy
(heat
against
system
moves
kinetic
particles
attached
of
transformations
pendulum
This
40
oscillates
into
the
very
due
the
to
swinging
which
slowly
pendulum.
these
energy
pendulums
for
drives
their
in
long
the
clocks
periods
pendulum.
gravitational
Swinging
When
even
you
are
though
your
centre
gain
kinetic
chemical
forces
on
a
there
of
you
energy
gravity
or
you
your
can
loss
can
gravitational
potential
with
swing
is
energy
keep
to
the
drive
the
potential
to
drive
it
moving
swing
energy.
the
for
a
surroundings.
swing
and
so
seem
you
you
time
adjusting
you
However,
when
long
By
are
to
using
produce
muscles.
ACTIVITY
Figure
Investigate
ball

down
the
a
Measure
energy
ramp
the
of
losses
due
different
height
to
friction
gradients
difference
to
by
rolling
(Figure
calculate
a
trolley
1.18.2
or
1.18.3).
the
loss
of
EXAM

gravitational
potential
Measure
speed
to
find
the
the
kinetic
of
the
trolley
or
ball
at
the
end
of
the
ramp
If
you
the
losses:
do
no t
know
energy.
where
Explain
TIP
energy.
does
a
steeper
ramp
waste
more
or
less
the
energ
y
energy?
miss
ing
has
gone
trans
fo rm
ation
probab
ly
into
KEY
Figure
1.18.3
Investigating
energy
Describe
changes
trans
fo rm
ed
POINTS
1
Energy
is
2
During
always
energy
energy
into
heat
and
this
longer
when
a
has
conserved.
losses
EXAMPLE
the
it
heat.
some
WORKED
in
a
heavy
ball
is
dropped
onto
in
transfers
is
transformed
the
surroundings
energy
be
can
no
used.
a
trampoline.
SUMMARY
The
ball
starts
transformed
with
into
gravitational
kinetic
energy
potential
as
it
falls.
energy
When
and
the
this
ball
hits
the
1
trampoline
the
trampoline
stretches,
this
is
because
the
How
is
being
transformed
into
elastic
potential
is
energy
lost
when
kinetic
you
energy
QUESTIONS
is
energy.
push
a
book
across
your
When
desk?
the
be
ball
has
no
transferred
upwards
energy.
energy
The
has
eventuallly
and
ball
the
into
of
kinetic
continue
continue
ball
but
energy
the
stop
the
elastic
energy
and
to
and
the
until
gravitational
be
each
will
moving.
all
will
of
heat
been
will
move
potential
its
of
When
is
energy.
you
and
to
and
place
a
stretches.
pulled
released
energy
until
it
then
up
the
tranferred
2
spring
kinetic
potential
to
have
energy
ball
stretching
converted
energy
strain
gravitational
upwards
during
will
initial
will
left
energy
transferred
some
all
energy
kinetic
will
been
will
trampoline
heat
back
gaining
The
cycle
kinetic
the
system
down.
explain
If
onto
the
why
and
oscillates
Describe
in
a
mass
downwards
transfers
eventually
mass
this
the
the
process
mass
stops.
41
1.19
Power
Some
LEARNING
devices
the
should
end
be
transfer
energy
efficiency
at
a
greater
rate
than
others.
For
OUTCOMES
example,
At
and
of
this
able
topic
one
you
a
large
second
car
than
a
engine
small
will
be
moped
able
to
engine,
transfer
as
it
is
more
more
energy
in
powerful.
to:
Power

calculate
power

calculate
the
energy
efficiency
transfer
or
of
an
The
rate
of
energy
transfer
is
called
power
and
is
defined
by
the
equation:
device.
work
power
done
(energy
transferred)
=
time
taken
E
or
P
=
t
−1
The
unit
The
power
done
and
transfer
WORKED
EXAMPLE
of
power
the
equation
so
or
is
can
be
J s
which
applies
used
to
for
any
has
the
transfer
mechanical
special
of
name
energy
work,
or
electrical
watt
any
energy
heating
1
An
electric
total
This
a
motor
mass
of
process
What
is
Weight
is
the
=
used
600 kg
takes
Remember
30
work
to
mass
lift
the
×
a
an
elevator
height
of
and
40 m
passengers
(Figure
with
1.19.1).
seconds.
done
use
to
through
by
the
weight
elevator
of
gravitational
the
motor?
elevator
field
and
not
the
strength
–1
40 m
Elevator
=
=
600 kg
=
6000 N
Now
calculate
W
Fd
×
the
10 N kg
weight:
with
5
passengers
=
=
6000 N
×
40 m
=
2.4
What
is
the
effective
power
rating
5
E
P
=
42
Lifting
2.4
×
10
=
t
1.19.1
×
10
J
600 kg
b
Figure
(W)
work
J
=
30 s
8.0 kW
of
the
elevator
motor?
mass:
Efficiency
During
any
energy
transfer
some
energy
is
wasted
and
lost
to
the
EXAM
environment.
there
is
This
always
wasted
some
energy
heat
depends
on
the
specific
device
produced.
If
The
efficiency
transferred
of
a
transfer
is
a
measure
transfer
As
output
and
there
the
is
input
the
how
the
and
lift
energy
is
so
represents
input
value
some
no
motor
transfer
is
have
try
the
total
the
an
or
power
energy
output
is
efficiency
or
power
always
of
output
Y
our
defini
tely
a
go
back
ques
tion
answ
er
no t
is
co rrec
t.
input.
smaller
greater
of
an
greater
then
the
100%
energy
find
of
100%
agai
n.
useful
wasted
can
than
than
100%.
2
mentioned
energy
the
ever
efficie
ncy
value
represents
energy
EXAMPLE
much
you
and
×
value
always
WORKED
If
much
value
=
input
the
how
than
output
Here
of
usefully:
efficiency
TIP
but
in
wasted
Worked
when
example
lifting
the
1
is
70%
elevator
efficient,
and
passengers?
First
find
out
how
much
output
efficiency
energy
supplied
to
the
motor:
value
=
input
was
×
100%
×
100%
value
5
output
input
value
value
2.4
=
×
10
J
=
×
efficiency
100%
70%
5
=
The
energy
law
of
3.4
×
wasted
10
by
conservation
of
J
the
motor
can
now
be
found
using
the
energy:
SUMMARY
Energy
wasted
=
energy
supplied
–
useful
energy
5
=
(3.4
–
2.4)
×
10
output
1
5
J
=
1.0
×
10
QUESTIONS
What
is
the
power
rating
of
J
an
engine
which
40 kJ
per
How
much
transfers
minute?
ACTIVITY
2
Use
a
small
(Figure
electric
1.19.2).
electrical
motor
Calculate
energy
supplied
attached
the
to
gain
the
to
in
a
joulemeter
potential
motor
to
find
to
energy
its
lift
objects
and
is
the
motor
efficiency.
75%
Does
the
efficiency
of
the
motor
change
when
the
load
by
with
in
power

useful
provided
an
an
one
efficiency
hour
rating
energy
electrical
of
if
it
of
has
a
150 W?
is
changed?
Joulemeter
Ruler
Wire
KEY
1
Motor
POINTS
The
power
rate
at
of
which
(transfers
a
it
device
does
energy)
as
is
the
work
given
by
E
P
=
t
2
Metal
Efficiency
how
useful
1.19.2
Measuring
the
efficiency
of
an
electric
a
effective
transfer
Figure
is
measure
of
block
is
at
an
energy
producing
energy.
motor
43
1.20
Pressure
Pressure
LEARNING
When
At
the
end
of
this
topic
be
able
you
calculate
the
walk
Your
on
a
sandy
weight
is
pressure
of
your
feet
causing
a
a
acting
you
down
leave
on
trail
of
sand
footprints
and
it
acts
over
the
=
F
or
p
=
surface
area

a
the
pressure.
force
Pressure
on
beach
pushing
to:
area

surfaces
you
behind.
should
on
OUTCOMES
describe
how
with
depth
the
pressure
in
a
increases
A
−2
The
unit
of
pressure
is
N m
which
is
also
known
as
the
pascal
(Pa).
fluid.
–2
Pressure
can
also
be
measured
in
N cm
2
.
As
2
1 m
=
10 000 cm
,
2
1 N cm
=
10 000 Pa.
ACTIVITY
Draw
to
around
estimate
Calculate
your
the
the
feet
area
onto
of
pressure
your
you
some
feet
exert
squared
and
on
then
the
paper
.
floor
A
re
a:
2
A
m
40
0
2
(2
=
Figure
×
13
.3
N
0
.0
1
5
)
m
2
kP
a
1.20.1
WORKED
EXAMPLE
1
Figure
I
F
=
N
=
0.0
15
squares
weight.
1.20.2).
P
40
0
the
your
(Figure
W
eig
ht:
150 cm
Use
measure
have
a
mass
of
60 kg
and
1.20.2
How
much
pressure
do
you
produce
on
the
floor?
the
2
total
area
of
my
feet
is
0.04 m
.
Pressure
What
is
the
pressure
on
Pressure
sand?
be
F
p
=
in
liquids
the
acts
throughout
demonstrated
simply
a
liquid
by
and
allowing
increases
water
to
with
flow
depth.
out
of
This
holes
can
in
a
600 N
=
=
15 kPa
container.
The
further
down
the
hole
is
from
the
surface
of
the
liquid
2
A
0.04 m
the
further
greater
the
force
water
or
squirts
out.
This
shows
that
it
is
experiencing
a
pressure.
ACTIVITY
Drill
Holes
some
small
with
water.
holes
into
a
tall,
plastic,
measuring
cylinder
and
at
fill
different
depths
it
depth
of
the
Compare
water
in
the
the
distance
container.
the
What
water
is
happens
ejected
as
the
to
the
water
Water
beneath
level
the
decreases
(Figure
1.20.3)?
surface
Squeezy
Another
bottle
Jets
pressure
experiment
uses
Pascal’s
vases.
of
water
Explaining
When
Figure
1.20.3
The
pressure
in
a
a
with
submarine
is
in
under
pressure
onto
the
skin
water
of
the
the
weight
submarine.
depth.
acting
44
increase
of
the
water
acts
liquid
downwards
increases
the
on
the
surface
of
the
submarine.
This
produces
pressure

Imagine
width

The
the
w
water
and
volume
given
above
length
of
the
l
the
giving
water
submarine
an
area
directly
of
l
above
to
be
×
w
the
a
rectangle
(Figure
with
1.20.4).
submarine
would
be
by:
Column
volume
=
length
×
width
×
height
or
V
=
l
×
w
×
liquid

The
mass
of
the
water
above
the
submarine
would
be
of
h
given
of
density
by:
ρ
h
mass

The
force
weight
=
volume
acting
of
the
weight
×
density
downwards
water
=
mass
W
=
l
weight
of
the
which
×
or
on
m
the
would
l
×
w
×
submarine
be
gravitational
=
given
field
h
×
ρ
would
be
the
by:
strength
w
or
×
w
×
h
×
ρ
×
g
l

The

The
water
acts
over
the
surface
of
the
submarine,
l
×
w.
Figure
pressure
acting
on
force
pressure
the
l
=
×
submarine
w
×
shows
depth
At
(h)
very
that
as
the
long
great
compressed
ρ
×
pressure
as
the
liquid
the
is
so
increases
is
in
has
pressure
a
at
a
liquid
×
ρ
×
at
a
g
high
is
the
that
particular
same
the
throughout.
liquid
is
slightly.
2
density
a
h
constant
liquid
3
Mercury
within
w
of
pressure
density
EXAMPLE
a
density
the
the
in
×
Pressure
g
=
l
depths
and
WORKED
×
=
area
This
h
1.20.4
is:
depth
of
13.5
×
of
30 mm
10
−3
kg m
beneath
.
What
the
is
the
surface
of
increase
a
pool
of
SUMMARY
QUESTIONS
mercury?
3
p
=
h
×
ρ
×
g
=
0.030 m
×
13.5
×
10
–3
kg m
1
–1
×
A
nail
plank
3
=
4.05
×
10
is
knocked
into
a
10 N kg
of
wood
using
a
force
–2
N m
of
60 N.
The
point
on
the
2
nail
has
an
area
−6
(1.0
Pressure
in
×
gases
when
The
m
nail
Earth’s
atmosphere
is
a
deep
layer
of
gases
reaching
Water
has
beyond
100 km
above
increases
in
difference
the
Earth’s
depth
in
in
density
a
as
surface.
similar
you
Pressure
way
travel
to
the
deeper
in
the
greater
a
is
the
wood
hit?
pressure
into
the
than
that
in
liquids
and
so
the
sea
level
referred
the
to
Blue
the
as
pressure
‘one
is
in
a
liquid
but
atmosphere
relationship
approximately
atmosphere’
Mountain
Peak
in
100 kPa
pressure.
Jamaica
If
you
you
is
not
as
which
is
climbed
would
is
pressure
40 m
above
sea
level.
At
this
height
the
air
of
is
the
reach
surface?
Don’t
pressure
is
the
forget
to
far
the
pressure
of
the
simple.
above
the
water.
often
to
a
beneath
the
the
top
height
of
KEY
2.2 km
density
What
atmosphere
(0.8
is
the
atmosphere
include
of
What
on
−3.
1000 kg m
At
).
acting
the
1.0 mm
atmosphere
2
The
10
pressure
of
2
only
POINTS
80 kPa
atmosphere).
1
The
pressure
acting
on
a
F
As
water
is
much
denser
than
air,
travelling
to
a
depth
of
10
metres
surface
in
water
will
Deep-sea
increase
divers
experience
a
can
the
pressure
reach
pressure
of
a
50
depth
acting
of
on
nearly
atmospheres.
you
to
500 m
two
is
given
by
p
=
A
atmospheres.
causing
them
to
2
The
pressure
given
by
p
=
in
a
liquid
is
hρg
45
1.21
Floating,
sinking
and
density
Archimedes
LEARNING
has
At
the
end
should
be
was
a
of
this
able
topic
it
gold,
you
that,
he
when
asked
discovered
explain
float
why
and
some
calculate
acting
why
some
its
lived
the
on
an
weight
a
key
principle
if
a
in
the
which
crown
3rd
was
century
explains
made
BCE.
why
from
Legend
objects
pure
float
or
sink.
resultant
force
object
a
and
principle
sink
as
object,
force
wholly
equal
to
the
or
partially
weight
of
immersed
the
fluid
in
a
fluid,
displaced
by
is
buoyed
the
up
by
a
object.
result
It
of
who
investigate
objects
Any

scientist
to
to:
Archimedes’

Greek
OUTCOMES
is
important
to
note
that
this
principle
applies
to
objects
which
are
buoyancy.
floating
In
and
addition
their
own
to
objects
which
submerged
volume.
This
are
objects
fact
is
submerged
will
displace
often
used
a
to
in
the
fluid.
volume
calculate
of
water
the
equal
density
to
of
materials.
When
you
weight
of
get
into
that
a
bath
displaced
of
water
water
will
you
be
will
the
notice
same
the
as
water
the
level
upthrust
rise.
you
ACTIVITY
Investigate
called
a
Archimedes’
Eureka
Measure
the
submerged
in
the
can)
weight
in
the
principle
(Figure
of
a
displacement
can
(also
1.21.1).
water
water.
using
displaced
Compare
this
when
to
the
an
object
apparent
is
reduction
weight.
Spring
balance
2
4
A
6
Weight
of
steel
8
2
block
=
8 N
1
0
4
Weight
of
steel
A
6
block
=
5 N
8
1
0
Displacement
filled
to
can
overflowing
Steel
Displaced
block
water
Steel
block
Beaker
Weight
0
of
Weight
empty
beaker
2
2 N
7
displaced
water
=
4
6
Large
on
vessels
the
side
Plimsoll
line
have
called
or
a
the
line.
Figure
46
1.21.1
Investigating
3
7
4
5
marking
water
5 N
6
5
1.21.2
2
8
plus
3
Figure
1
9
beaker
8
=
0
of
1
9
empty
Beaker
Archimedes’
principle
The
feel.
Floating
objects
WORKED
An
object
will
float
as
long
as
the
upthrust
(or
buoyancy)
is
equal
weight
of
the
object.
Solid
objects
with
a
density
greater
ferry
of
water
will
always
weigh
more
than
the
water
they
St
so
will
used
Lucia
to
to
transport
cars
Martinique.
The
displace
ferry
and
is
than
from
that
1
to
A
the
EXAMPLE
has
a
fully
loaded
mass
of
sink.
6
5000
Ships
are
built
from
steel
which
has
a
much
higher
density
than
water.
tonnes
density
of
3
They
float
because
their
average
they
density
contain
to
much
large
lower
volumes
than
the
of
air
and
density
of
this
reduces
water.
10
of
the
ship
weighs.
to
float
Loading
the
ship
and
the
ship
will
it
up
must
the
therefore
sink
the
lower
displace
ship
with
weight
into
the
the
cargo
of
same
will
water
weight
increase
of
water
the
displaced.
as
weight
This
10
is
kg).
1.02
The
×
.
water
What
the
to
is
ferry
the
volume
needs
remain
to
floating?
it
of
means
×
−3
kg m
displace
For
(5.0
seawater
that
The
of
water.
mass
must
be
the
of
the
the
water
same
as
displaced
the
mass
ferry.
mass
If
too
the
much
sea.
ensures
cargo
The
is
added
Plimsoll
that
line
enough
to
the
ship
indicates
extra
then
how
buoyancy
is
it
will
heavily
kept
sink
loaded
in
reserve
too
the
in
low
ship
case
in
is
Density
=
volume
and
waves
6
m
cause
water
to
start
entering
the
ship
(Figure
V
1.21.2).
5.0
=
×
10
kg
=
3
ρ
If
the
ship
is
damaged
and
water
enters
into
the
hull
then
1.02
×
−3
10
kg m
the
3
=
weight
of
the
eventually,
becomes
it
ship
increases
sinks.
greater
The
than
and
average
the
it
sinks
density
density
of
lower
of
the
the
into
ship
the
as
a
water
4.9
an
object
objects
is
A
beneath
the
surface
3
m
whole
of
a
fluid
Archimedes’
EXAMPLE
hydrogen
mass
When
10
water.
WORKED
Submerged
×
until,
of
balloon
40.0 kg
2
has
and
a
a
total
volume
principle
3
of
tells
us
there
will
be
an
upthrust
force
acting
on
the
object
equal
40 m
.
If
the
surrounding
air
to
−3
has
the
weight
of
the
fluid
displaced.
This
upthrust
force
will
seem
a
the
weight
of
the
object
by
decreasing
the
resultant
of
1.225 kg m
,
to
how
reduce
density
large
is
the
upwards
force
force.
acting
First
Submarines
on
find
the
the
balloon?
mass
of
the
air
displaced:
Submarines
can
alter
their
average
density
by
allowing
ballast
tanks
−3
m
to
fill
with
water.
This
increases
the
weight
of
the
submarine
=
ρ
×
V
=
1.225 kg m
×
which
3
40 m
makes
be
it
sink
pushed
the
in
out
weight
of
the
of
water.
the
the
To
tanks
gain
using
additional
buoyancy
compressed
air
and
the
this
water
=
49 kg
can
decreases
This
means
displaced
submarine.
weight
is
of
the
weight
490 N
the
(W
balloon
of
=
is
the
air
mg).
The
400 N.
Balloons
Finally
A
balloon
that
the
or
there
weight
balloons
their
airship
will
of
and
be
air
a
is
also
force
which
airships
to
submerged
acting
has
been
float
as
in
upwards
a
fluid,
on
displaced.
long
as
the
the
the
air.
This
balloon
This
buoyancy
upthrust
is
means
equal
to
resolve
upwards
weight
the
force
=
=
490 N
forces:
upthrust
−
400 N
−
=
90 N
allows
greater
than
weight.
KEY
1
SUMMARY
POINTS
The
density
of
a
material
is
QUESTIONS
m
given
by
ρ
=
V
1
Draw
a
diagram
showing
all
of
the
forces
acting
on
a
submarine
2
which
is
accelerating
forwards
while
sinking
in
the
An
a
2
A
balloon
of
mass
10 g
is
filled
with
helium
of
object
floating
on,
or
in,
ocean.
mass
0.4 kg
fluid
displaces
a
weight
of
so
fluid
equal
to
the
object’s
3
that
its
volume
is
5.0 m
.
Will
the
balloon
float
in
the
air?
weight.
47
Section
SECTION
1
A
1:
Practice
student
motion
bearing
the
has
of
mounted
a
is
is
follows
fl oor.
travelled
the
compressions
the
of
compression
bearing
The
ball
the
of
the
travels
bearing
compression
of
and
the
as
spring
is
the
2
a
Describe
the
energy
transformations
3
transfers
that
take
takes
off
and
place
when:
a
a
helicopter
b
a
bungee
c
a
tree
that
jumper
dives
off
a
bridge
The
falls
over
in
a
forest.
bearing
to
the
3
distance
and
range
A
a
of
car
of
force
the
mass
of
car
600 kg
500 N.
rises
by
The
is
pushed
slope
is
up
a
50 m
hill
long
using
and
4 m.
investigates
length
of
times
a
How
much
b
How
much
does
the
work
is
done
in
pushing
the
car?
the
distance
reaching
three
the
spring
x.
falls
for
and
before
fi red
it
the
the
spring
ball
questions
ball
so
distance
bearing
the
a
The
spring
a
between
from
exam
3
investigate
table.
measures
ball
relationship
ball
a
trajectory
student
by
into
released
curved
The
of
to
fi red
compressed
then
a
edge
pushed
questions
asked
bearing
the
is
Practice
exam
been
ball
at
spring
spring
1
the
for
gravitational
potential
energy
the
car
gain?
fl oor.
c
each
Assuming
is
spring.
counted
efficiency
4
x
that
During
a
world’s
tractor
as
of
gain
useful
the
required
and
distance
of
a
the
20 m
work,
to
road.
tractor
in
a
A
is
energy
calculate
the
transfer.
determine
human
flat
potential
energy
competition
strongest
along
in
the
competitor
force
of
moved
pulls
4000 N
through
a
is
a
70 s.
1 m
a
What
is
the
work
done
the
effective
in
moving
the
tractor?
b
What
d
Compression
is
distance,
x/cm
2.0
3.0
4.0
5.0
6.0
Travel
distance,
d/cm
26.2
38.8
51.0
63.4
76.2
Travel
distance,
d/cm
26.6
38.8
51.0
63.4
75.8
Travel
distance,
d/cm
26.6
39.0
51.2
63.4
76.0
a
Calculate
the
average
travel
distance
ball
bearing
of
the
for
5
the
power
competitor?
for
each
State
the
law
of
conservation
of
energy.
compression
Describe
how
this
law
is
applied
when
finding
distance.
the
b
Plot
a
graph
distance
comparing
(x-axis)
to
the
the
6
distance
A
new
business
electricity.
c
Draw
straight
d
Calculate
the
line
of
gradient
best
of
They
a
wind
turbine
To
what
the
extent
hypothesis
proportional
spring?
48
does
that
to
the
the
the
an
electric
motor.
a
paragraph
wished
are
or
to
generate
considering
photovoltaic
the
its
own
use
cells.
of
Write
fit.
this
data
travel
for
each
system
describing
line.
advantages
e
of
compression
travel
(y-axis).
a
efficiency
support
distance
compression
of
is
the
and
disadvantages.
the
3
7
A
pulley
system
consisting
of
three
pulleys
is
10
A
ship
is
made
of
4000 m
steel
of
density
−3
used
to
lift
through
a
a
pallet
height
of
of
bricks
40 m.
weighing
The
force
600 N
7900 kg m
required
to
a
What
volume
of
fresh
water
(ρ
=
water
lift
the
pallet
at
a
steady
speed
is
210 N
and
the
−3
1000 kg m
rope
is
pulled
through
a
distance
of
Neglecting
the
mass
of
the
pulleys
calculate
the
useful
work
done
the
What
is
Explain
to
In
the
what
in
order
how
the
displace
efficiency
of
the
pulley
to
for
it
to
float?
design
this
of
much
the
ship
enables
water.
A
rectangular
form
is
energy
wasted
in
block
of
polystyrene
foam
with
system?
dimensions
c
need
pallet.
11
b
ship
in
it
lifting
the
and
b
rope,
would
120 m.
displace
a
)
the
2.0 m
×
1.0 m
×
0.3 m
is
used
to
lifting
make
a
raft.
process?
The
density
of
the
polystyrene
−3
is
−3
50 kg m
and
What
is
b
What
volume
when
the
How
raft
the
that
a
c
foam
mass
of
block
much
of
water
of
the
water
1000 kg m
polystyrene
will
be
block?
displaced
floats?
additional
support
is
before
weight
beginning
could
to
the
sink?
Pull
12
Explain
the
13
why
a
helium-filled
balloon
rises
in
atmosphere.
The
following
from
table
hydroelectric
shows
plants
Location
the
on
power
output
Jamaica.
Installed
Power
output/MW
Upper
White
River
1945
3.8
Lower
White
River
1952
4.9
1949
3.8
1949
2.5
1966
6.3
1989
0.8
1989
0.6
1989
1.1
Roaring
River
600 N
Rio
8
A
tourist
submarine
has
a
glass
dome
Bueno
Maggotty
allow
clear
views
of
aquatic
life.
The
withstand
pressure
of
a
maximum
12 000 kPa.
The
absolute
density
3
seawater
is
1.02
×
kg m
Rams
of
is
the
maximum
safe
= 10 N kg
).
diving
depth
of
a
−3
The
density
Which
float
of
in
of
the
water
is
1000 kg m
following
cubes
of
material
Find
the
will
b
Assuming
year
of
side
b
output
of
the
system.
the
(365
turbines
days),
production
of
operate
estimate
the
system
all
the
total
over
a
year
.
Mass
c
a
power
that
around
energy
Length
total
)
water?
Material
River
hydroelectric
−3
(1 g cm
Bueno
the
submarine?
9
Horn
–1
(g
Rio
What
Spring
external
−3
10
Falls
dome
Constant
can
A
to
4.0 cm
10 cm
The
total
electrical
energy
production
16
60 g
in
Jamaica
was
percentage
1.2 kg
produced
of
by
2.0
×
10
Jamaica’s
J.
What
electricity
is
hydroelectricity?
4
c
3.1 m
2.3
×
10
kg
d
Suggest
why
stations
have
no
new
been
hydroelectric
built
since
power
1989.
49
2
Thermal
physics
and
kinetic
theory
2.1
Heat,
energy
and
temperature
A
LEARNING
good
understanding
behaviours
At
the
should

end
be
outline
the
of
thermal
energy
is
required
to
explain
the
OUTCOMES
of
this
able
the
kinetic
topic
them.
you
to:
development
theory
of
It
of
took
were
hot
The
end
different
many
and
why
materials
years
for
objects
and
the
scientists
energy
to
transfers
explain
why
between
some
objects
cooled.
of
thermal
of
the
caloric
theory
energy
During

describe
energy
the
flow
from
one
of
heat
object
was
to
called
another.
The
the
the
some.
Count
heat
hot
holes
cannon
Over
to
the
next
developed
be
generated
2.1.1
The
mechanical
work
boring
was
out
this
converted
to
by
provided
(Figure
2.1.2).
would
the
meant
to
heat
water
the
always
other
found
the
If
that
heat
a
was
water
of
Joule
This
a
no
to
gain
involved
large
amount
properties
physical
to
ideas
behind
the
principle
of
water
point.
There
James
Joule,
energy
the
that
temperature
increase
was
research
of
eventually
led
energy.
cannon
heat.
Paddle-wheels
Mass
moves
at
to
a
energ
y
from
high
er
an
objec
t
an
alwa
ys
objec
t
tempe
rature
at
a
lower
tempe
rature.
Liquid
Insulated
Figure
50
2.1.2
Joule’s
apparatus
for
container
transferring
(no
could
mechanical
TIP
T
herm
al
of
the
temperature
conservation
in
substance
under
boiling
measured
in
object
released.
internal
the
moves.
meaning
work
placed
including
increase
supplied.
clearly
were
heat
fluid
heat
one,
cold
a
caloric.
identical
being
measured
the
Thermometer
EXAM
the
form
energy.
and
was
there
heat
the
of
about
was
when
colder
and
had
scientists,
was
that
energy
there
idea
there
mechanical
cannons
of
a
supply
of
cannon
supply
mechanical
He
to
Although
This
that
effect
held
that
objects
to
caloric
limited
heating
from
years
object
some
a
idea
done
the
in
the
lose
the
between
hot
have
unlimited
idea
commonly
used
a
transferred.
work
energy
proportional
Figure
only
filings
few
the
would
material.
an
most
from
cannons.
being
be
the
theory
transferred
flow
noted
the
mechanical
seemed
was
could
into
released,
caloric)
This
object
Rumford
original
(the
that
would
Objects
boring
century
theory.
caloric
caloric
that
the
18th
caloric
heat
in)
mechanical
energy
into
heat
to
The
The
kinetic
thermal
theory
energy
and
(heat
thermal
energy)
of
an
energy
object
is
mainly
the
result
of
ACTIVITY
the
motion
motion
it
of
is
the
called
particles
the
within
kinetic
the
object.
theory.
Some
As
the
theory
potential
describes
energy
is

associated
with
the
bonding
between,
and
the
arrangement
of,
Use
three
water,
atoms
in
means
to
an
this
energy
that
transfers
thermal
object
at
a
from
energy
lower
a
hotter
flows
object
from
temperature.
an
This
to
a
object
cooler
at
process
high
one.
This
temperature
always
occurs
one
(Figure

in
Place
temperature
After
coldness
are
scale
of
is
simply
objects.
several
a
way
Hotter
temperature
of
expressing
objects
scales
have
a
the
higher
relative
hotness
temperature.
including:
Celsius
freezing
100 °C
scale:
This
point
of
producing
The
used
Kelvin
ideal
gases
absolute
hand
is
a
scale
based
on
the
properties
of
pure
a
water
centigrade
temperature
scale:
and
The
the
zero.
kelvin
This
and
is
so
Kelvin
energy
At
this
is
set
at
(100
scale
scale
of
in
0 °C
step)
is
school
based
particles.
temperature
Temperate

Temperature
in
SUMMARY
What
if
2
the
Copy
to
cannot
be
the
conversion

1
they
defined
makes
kelvin
in
water
in
in
the
the
hot
iced
seconds
and
the
scale.
boiling
Celsius
is
on
The
the
science
the
low
and
place
of
become
same
between
=
as
any
an
the
Celsius
increase
scales
temperature
degrees
colder.
have
in
An
zero
of
fairly
degrees
one
=
temperature
in
Count
in
which
will
has
feel
has
feel
hands
been
cold
been
in
and
in
the
the
hot.
the
cold
However
,
are
experiencing
the
temperature.
is
thermal
of
water
one
Hot
Room
water
temperature
Celsius.
Figure
kelvin
will
of
scale
degree
+
which
most
easy:
Celsius
lukewarm
industry.
the
increase
the
point
the
properties
point
particles
in
into
2.1.3
Hot
or
cold?
273
−
273
QUESTIONS
would
caloric
and
hot
water.
Ice-cold
energy
one
thirty
water
same
commonly
hand
hands
hot
both
at
containing
and
The
water
The
iced
water
water.
hand
The
of
scales
both
There
one
lukewarm
water.

and
of
2.1.3).
one
water
direction.
T
emperature
A
one
materials.
and
Thermal
bowls,
the
have
happened
theory
complete
had
been
T
able
Rumford’s
experiments
correct?
2.1.1
which
shows
some
important
temperatures.
KEY
T
able
POINTS
2.1.1
1
T
emperature
in
The
thermal
object
degrees
Celsius
in
is
zero
point
of
liquid
nitrogen
Freezing
point
of
ethanol
Freezing
point
of
water
Body
measure
of
of
an
the
energy
and
potential
0
energy
Boiling
a
kelvin
kinetic
Absolute
energy
T
emperature
77
−117
point
of
ethanol
Boiling
point
of
water
2
310
3
of
all
make
of
up
Temperature
the
0
temperature
Boiling
that
‘hotness’
the
the
is
a
of
Thermal
energy
from
object
an
particles
object.
measure
an
is
at
of
object.
transferred
higher
79
temperature
to
an
object
at
100
lower
temperature.
51
2.2
Thermometers
LEARNING
temperature
scales
A
the
thermometer
the
end
should
be
is
a
device
of
this
able
topic
substance.
describe
and
the
select
an
of
of
appropriate
for
use
in
will
an
object
with
thermometers
thermometers
expand
is
proportional
A
reservoir
as
to
its
are
based
the
temperature
on
the
increase
in
increases
principle
and
temperature
that
that
(Figure
this
the
expansion
2.2.1).
a
of
liquid,
mercury
or
coloured
alcohol,
is
contained
at
the
situations.
will
is
be
of
the
and
tube.
schools
are
in
a
rise
up
give
ice
This
boiling
used
liquid
to
point
water
the
can
a
The
the
point.
‘bulb’.
tube
tube
the
calibrated
level
The
the
0 °C.
of
This
measurable
higher
marking
represents
and
100 °C
be
a
capillary
capillary
then
in
give
upwards.
the
and
to
narrow
thermometer
melting
thermometers
thermometer
enough
further
The
Most
the
connected
expand
2.2.1
of
vary
different
bottom
Figure
that
thermometer
thermometer
range
temperature
properties
characteristics
liquid

on
temperature.
you
Liquid-in-glass
of
rely
to:
operation
types
measure
Thermometers
Liquid-in-glass

to
OUTCOMES
or
At
and
The
distance
will
of
the
of
the
that
The
which
the
of
there
reservoir
the
bulb
liquid
liquid
in
is
capillary
between
so
liquid
the
will
liquid
rise.
placing
bulb
in
expansion.
temperature
liquid
level
liquid
required
through
the
by
is
these
of
liquid
the
then
tube
two
in
capillary
placed
is
in
marked
points
is
to
then
liquid-in-glass.
divided
into
Clinical
As
to
body
between
cover
allows
equal
divisions
giving
a
centigrade
scale.
thermometers
human
vary
100
only
the
this
and
narrow
to
divisions
magnify
is
42 °C,
thermometer
temperature
designed
temperature
35 °C
of
the
approximately
a
clinical
range
to
be
(Figure
2.2.2).
designed
0.1 °C.
The
capillary
to
be
shape
tube
37 °C
and
thermometer
of
and
The
very
the
is
will
generally
designed
small
range
precise,
with
thermometer
make
it
easier
to
is
read
the
temperature.
Clinical
they
thermometers
can
be
contracts,
breaks
the
the
a
most
2.2.2
A
clinical
follows
prevent
thread.
are
now
removed
inaccurate
is
built
liquid
into
can
from
reading
the
be
the
patient
as
the
liquid
thermometer
returned
to
before
the
that
bulb
after
thermometer.
take
display
being
The
the
be
an
constriction
flicking
and
to
an
a
few
minutes
accurate
replaced
by
to
reach
temperature.
electronic
thermal
Because
of
this,
thermometers.
thermometer
the
principles
by
To
thermometers
equilibrium
Figure
small
liquid
reading
Clinical
read.
need
same
as
a
basic
liquid-in-
Thermocouples
glass
thermometer.
A
thermocouple
potential
connected.
52
is
an
difference
The
p.d.
electrical
(p.d.)
thermometer
produced
produced
varies
when
with
which
two
relies
different
temperature.
on
the
metals
are
Thermocouples
melting
p.d.
or
on
they
a
that
There

can
This
display
and
also
can
be
then
making
thermocouples
very
they
temperatures
recorded
be
very
quite
converted
them
are
high
respond
very
used
simply
and
easy
to
(beyond
quickly
a
by
in
the
changes.
data
These
The
loggers
temperature
read.
extensively
to
shown
properties
industry.
thermometers
are
Gas
measure
glass)
produce
digital
More
can
of
computers.
mean

point
several
other
thermometers
types
use
temperature
increases.
temperature
change.
Infra-red
ACTIVITY
of
the
This
thermometers
thermometers:
fact
that
expansion
measure
a
gas
is
the
expands
when
proportional
rate
of
to
emission
its
your
using
a
dyed
the
of
Make
radiation
from
objects.
The
intensity
of
this
radiation
water
the
temperature
This
of
the
object:
measurement
can
hotter
be
objects
used
to
find
emit
the
the
flask
in
iced
level
of
the
something
SUMMARY
1
What
the
are
three
without
needing
to
touch
tube.
water
dyed
and
water
infra-
0 °C
point.
Then
place
it
in
depends
water
to
find
the
level
more
100 °C.
Divide
the
range
into
temperature
suitable
of
containing
capillary
the
for
radiation.
and
mark
boiling
on
thermometer
flask
Place
for
red
own
conical
divisions.
it.
QUESTIONS
the
ranges,
precisions
liquid-in-glass
and
temperature
thermometers
a
b
°C
shown
in
readings
Figure
on
2.2.3?
c
°C
42
200
100
41
190
40
180
39
170
38
160
37
150
36
35
140
34
130
33
120
32
110
10
1
00
0
KEY
1
Figure
What
to
All
thermometers
on
physical
rely
changes
in
substances
caused
changes
temperature.
in
by
2.2.3
2
2
POINTS
a
are
the
advantages
liquid-in-glass
of
using
thermometer?
a
thermocouple
compared
Thermometers
of
scales,
response
have
precisions
a
range
and
times.
53
2.3
The
Most
LEARNING
states
materials
the
end
should

be
of
this
able
describe
the
topic
of
The
arrangement
the
particles
use
liquids
the
and
particle
describe
the
behaviour
and
into
of
solids,
three
categories
liquids
and
based
on
their
gases.
model
of
matter
and
materials
are
composed
of
tiny
particles
in
different
arrangements.
in
particles
are
atoms
or
molecules.
The
behaviour
and
physical
gases
properties

placed
behaviour:
particle
These
solids,
and
you
to:
All
behaviour
be
matter
OUTCOMES
properties
At
can
of
model
properties
solids,
of
to
these
of
materials
particles
and
can
the
be
explained
forces
by
between
describing
the
behaviour
them.
and
Properties
liquids
of
solids
gases.
In
solid
are
materials
held
in
place
(Figure
2.3.1a).
vibrate
about
the
particles
with
The
are
relatively
particles
closely
strong
are
not
packed
together
inter-molecular
free
to
move
and
forces
around
but
instead
a
maintain
It
is
not
already
the
Solid
their
their
easy
own
to
tightly
particles
strongly
fixed
positions.
compress
move
means
that
solid
materials
shape.
packed
repulsive
This
solids.
together.
slightly
force
This
If
closer
a
is
because
together.
between
the
compressive
them
particles
force
However,
and
so
is
this
further
are
applied
then
produces
a
compression
b
becomes
volume
much
more
(although
Properties
of
difficult.
this
can
Because
change
of
when
this
the
solids
solid
is
have
a
fixed
heated
or
cooled).
liquids
Liquid
The
c
particles
molecular
will
and
are
are
forces
2.3.1b).
flow
Liquids
liquids
forces
short-range
(Figure
in
very
also
weaker
allow
When
the
are
a
liquid
the
difficult
than
to
is
fi ll
packed
those
particles
liquid
will
closely
placed
the
for
to
compress
solids.
flow
into
bottom
for
together
a
of
the
past
but
These
each
inter-
weaker,
other
container
the
the
the
particles
container.
same
reasons
as
solids.
Gas
When
Figure
2.3.1
The
arrangement
they
in
a
a
solid,
b
and
c
a
This
The
use
describ
ing
the
move
not
54
occur
between
that
liquids
also
have
a
fixed
volume
as
the
long
as
is
unchanged.
gases
in
gases
around
have
very
very
quickly
weak
inter-molecular
(Figure
2.3.1c).
The
forces
gas
and
particles
compared
term
‘parti
cles’
indivi
dual
mo lec
ules.
each
space.
The
other
and
spaces
so
spread
between
out
gas
to
fill
particles
up
are
all
of
very
the
large
when
matter
,
to
the
size
of
the
particles
themselves.
The
space
between
to
particles
means
atom
s
pressure
or
of
attract
available
the
to
forces
TIP
do
refer
means
temperature
particles
they
When
repulsive
gas.
Properties
EXAM
strong
a
their
liquid
squashed
of
particles.
particles
are
to
it.
that
it
is
possible
to
compress
a
gas
by
applying
a
Thermal
When
solid
a
material
this
staying
expansion
in
particles
(Figures
is
increase
the
heated
in
same
slightly
2.3.2
particles
causes
position.
further
and
the
energy
This
apart
gain
the
increase
and
as
thermal
particles
a
in
to
energy.
vibrate
vibration
result
the
will
material
In
a
more
Ball
while
force
the
expands
2.3.3).
Ring
The
forces
which
produce
the
expansion
are
very
large
and
can
cause
Figure
even
very
strong
objects
to
distort.
Long
metal
bridges
may
2.3.2
A
metal
ball
through
by
several
bridges
centimetres
have
on
expansion
a
hot
gaps
day.
at
To
each
allow
end.
for
As
this
the
expansion
bridge
the
warms
up
the
ball
expand
it
longer
lengthens
prevent
As
you
them
have
heated.
Gases
and
The
in
gaps
buckling
already
in
hot
of
a
will
Similar
are
used
in
railway
lines
ring.
pass
will
and
fit
Heating
cause
it
will
it
to
no
through
the
ring.
to
weather.
both
liquid
not
gaps
a
liquids
will
be
and
gases
increase
able
to
with
expand
will
expand
when
temperature.
and
so
their
pressure
instead.
SUMMARY
QUESTIONS
Summarise
table
T
able
close.
seen,
volume
containers
increases
1
the
can
expand
like
the
T
able
properties
2.3.1.
of
Add
solids,
liquids
additional
and
gases
categories
if
using
you
a
can.
2.3.1
Shape
Does
Volume
Density
it
Separation
Forces
of
between
particles
flow?
particles
Solid
Liquid
Figure
2.3.3
Overhead
power
cables
Gas
or
telephone
on
2
Draw
gas
3
a
as
Use
diagram
it
is
ideas
showing
compressed
about
what
inside
expansion
to
a
happens
to
the
particles
in
a
to
hot
days,
lines
expand
causing
them
sag.
syringe.
explain
why:
ACTIVITY
a
running
the
lid
of
a
jar
under
hot
water
makes
it
easier
to
You
open
of
b
a
house
roof
sometimes
creaks
during
the
can
test
solids,
compressibility
and
gases.
night.

Seal
the
syringe.
as
end
of
Place
modelling
syringe
KEY
the
liquids
and
a
a
plastic
solid
clay
push
such
inside
on
the
the
POINTS
plunger.
1
In
solids
the
particles
vibrate
about
fixed

positions.
Repeat
water,
2
Liquids
and
gases
are
both
fluids.
Their
particles
are
free
with
and
a
a
liquid,
gas
such
as
(air).
to
The
solid
and
liquid
will
be
move.
incompressible
3
Gases
can
between
be
the
compressed
particles.
as
there
is
a
large
amount
of
space
possible
about
to
half
but
it
compress
of
its
should
the
original
gas
be
to
volume.
55
2.4
Gas
The
LEARNING
gas
laws
the
end
should
be
of
this
able
topic
will
you
or
result
state
the
describe
gas
laws
how
use
the
gas
changes
the
behaviour
in
the
altered.
change
the
or
can
The
be
gas
in
of
A
one,
temperature
volume
laws
number
laws
a
is
of
gases
the
change
or
of
a
both,
gas
in
when
of
will
one
the
of
their
these
temperature,
others.
cause
an
quantities
For
example,
increase
in
the
gas.
and
they
demonstrated

volume
in
increasing
to:
pressure

describe
OUTCOMES
pressure
At
laws
to
of
apply
to
particles
a
in
fixed
the
mass
gas
of
gas.
sample
This
does
means
not
that
the
change.
describe
properties
of
Charles’
law
gases.
Charles’
law
temperature
The
volume
describes
T
of
of
temperature
a
(in
a
gas
fixed
the
relationship
and
is
mass
kelvin)
if
usually
of
the
gas
is
between
stated
is
volume
V
and
as:
directly
pressure
the
proportional
kept
to
its
constant.
V
V
∝
T
or
=
=
constant
T
Volume
(length
of
air
column/cm)
Experimental
The
graph
can
be
extrapolated
data
back
to
zero
volume
Zero
volume
WORKED
EXAMPLE
1
–273
A
sample
of
gas
0
Temperature/ °C
+100
occupies
0
+273
Temperature/K
+373
3
600 cm
while
its
temperature
Figure
is
300 K.
400 K
The
and
gas
is
allowed
heated
to
expand
the
pressure
remains
What
volume
key
would
is
consequence
cooled,
the
of
kinetic
this
law
energy
is
of
the
the
idea
of
absolute
particles
zero.
decreases
As
until
a
they
the
stop
gas
law
the
gas
same.
Charles’
so
One
that
2.4.1
to
moving
altogether.
At
this
point
the
gas
will
have
zero
volume
occupy?
and
cannot
possible
Before
be
cooled
temperature:
any
further
absolute
(Figure
zero,
2.4.1).
This
is
the
lowest
0 K.
expansion:
3
V
600 cm
3
=
=
T
2 cm
–1
K
After
expansion:
V
3
=
2 cm
law
law
gas
its
and
The
–1
=
T
×
deals
with
pressure
volume
pressure
3
V
Boyle’s
of
a
p
fixed
2 cm
if
the
mass
temperature
–1
relationship
the
of
between
temperature
gas
is
is
inversely
the
kept
volume
V
of
a
constant.
3
=
400 K
×
=
800 cm
3
2 cm
is
kept
proportional
to
its
constant.
1
K
V
–1
∝
or
=
pV
=
constant
p
K
An
so
56
the
while
K
T
So
Boyle’s
300 K
increase
applying
in
pressure
pressure
will
cause
squashes
the
the
volume
gas
into
a
to
decrease
smaller
in
space.
proportion
The
pressure
The
pressure
The
pressure
temperature
law
law
of
a
(in
connects
fixed
temperature
mass
kelvin)
of
when
gas
the
is
T
and
directly
volume
is
pressure
p.
proportional
kept
to
the
constant.
p
p
∝
T
or
=
=
constant
T
This
means
pressure
the
that
to
heating
increase.
pressure
As
decreases
a
gas
the
to
in
a
closed
temperature
zero
(Figure
container
decreases
will
to
cause
the
absolute
zero
2.4.2).
Pressure, p
Zero
pressure
predicted
at
SUMMARY
absolute
zero
1
0
QUESTIONS
(0 K)
+73
+173
+273
Temperature/K
+373
What
a
happens
the
volume
decreased
Figure
2.4.2
The
pressure
when:
of
a
gas
while
is
the
law
temperature
remains
constant?
The
gas
equation
b
All
three
gas
of
the
gas
equation
volume
and
laws
that
can
be
describes
temperature
of
a
combined
the
together
relationship
gas.
As
before,
to
form
between
the
mass
the
of
a
the
single
is
pressure,
the
volume
be
of
while
remains
a
gas
the
constant?
gas
c
must
temperature
increased
the
pressure
of
a
gas
constant.
is
increased
while
the
pV
=
constant
temperature
is
kept
T
constant?
3
WORKED
EXAMPLE
2
2
A
500 cm
sample
compressed
A
weather
balloon
containing
hydrogen
gas
is
released
from
ground
into
the
balloon
at
the
atmosphere.
The
volume
of
the
gas
of
it
gas
is
occupies
3
only
the
until
100 cm
while
the
in
temperature
is
kept
constant.
3
launch
is
40 m
while
the
pressure
of
the
gas
is
The
5
1.0
×
10
final
of
the
gas
is
−2
Pa
(N m
)
and
the
temperature
is
35 °C
(308 K).
found
The
pressure
balloon
temperature
rises
is
into
the
−50 °C
upper
(223 K)
atmosphere
and
the
where
pressure
is
the
the
to
initial
be
600 Pa.
pressure
What
of
the
was
gas?
only
4
1.0
Let
×
10
the
Pa.
What
conditions
is
the
new
volume
on
the
ground
the
upper
be
of
the
balloon?
represented
by
V
,
p
1
and
T
1
1
KEY
and
the
conditions
in
atmosphere
by
V
,
p
2
Find
the
value
of
the
constant
at
ground
5
p
V
1
1.0
×
10
2
2
1
3
×
40 m
4
constant
=
The
be
1
=
POINTS
T
level:
–2
N m
and
=
1.3
×
10
behaviour
described
gases
the
can
gas
laws
–1
N m K
which
T
of
by
link
the
pressure,
308 K
1
temperature
Use
the
value
of
the
constant
to
find
the
new
a
p
and
volume
of
volume:
gas.
V
2
2
=
2
constant
The
gas
laws
lead
to
the
idea
T
of
2
4
T
×
constant
223 K
×
1.3
×
10
V
3
=
=
=
2
4
p
1.0
×
10
minimum
temperature
–1
N m K
2
So
a
–2
N m
called
absolute
zero
(0 K,
290 m
−273 °C).
2
57
2.5
Heat
Heat
LEARNING
the
end
of
this
topic
be
able
heat
capacity,
C,
of
an
object
is
the
amount
of
energy
increase
the
temperature
of
the
object
by
1 °C
(1 K).
to:
heat
energy
E
perform
calculations
capacity
=
or
heat
heat

capacity
capacity
describe
how
capacity
of
and
Specific
object
and
heat
capacity
of
can
be
heat
of
2 kg
an
object
block
of
temperature
water
specific
required
Specific
is
directly
aluminium
proportional
takes
twice
to
as
the
mass.
much
by
1 K
as
a
1 kg
block.
This
leads
energy
to
heat
of
specific
heat
to
capacity,
increase
capacity
energy
heat
the
allows
required
capacities
This
is
a
temperature
us
to
are
c.
to
directly
increase
shown
measure
of
of
compare
their
in
1 kg
of
a
the
the
materials
temperatures.
T
able
amount
material
by
and
Some
2.5.1.
1
Specific
of
a
its
amount
typical
EXAMPLE
of
energy
the
full
capacity
capacity
increase
1 K.
bath
(K)
measured.
of
A
heat
example,
concept
WORKED
Δθ
a
to
material
rise
the
For
specific
=
heat
The
an
)
specific
equations
the
(J K
using
temperature
the
C
(J)
H
–1
Heat

required
you
to
should
capacity
OUTCOMES
The
At
capacity
has
heat
capacity
is
defi ned
by
the
relationship:
been
heat
energy
6
provided
with
5.0
×
10
J
specific
of
heat
capacity
=
mass
energy
of
the
and
the
water
has
(8.0 K).
capacity
of
risen
What
the
change
E
by
–1
or
8.0 °C
×
in
temperature
temperature
is
the
c
(J kg
H
–1
K
(J)
)
=
heat
m
(kg)
×
Δθ
(K)
water?
Investigating
heat
capacity
and
specific
E
H
C
=
heat
capacity
Δθ
The
heat
capacity
of
a
metal
block
can
be
found
using
an
electrical
6
5.0
C
×
10
J
heating
=
element
(Figure
2.5.1).
The
energy
provided
is
measured
with
8.0 K
a
5
C
=
6.3
×
10
joulemeter
provided
A
Some
examples
of
similar
to
heater
rise
in
insulate
method
element
container
−1
air
electrical
power
heat
can
current
the
the
be
block
block
used
is
to
to
×
heater
p.d.
measured
reduce
find
the
×
with
a
is
placed
to
in
a
sample
of
heat
capacity
water
inside
such
as
a
plastic
beaker
or
a
polystyrene
the
385
gold
129
Thermometer
To
circuit
Metal
block
Heater
4181
Insulation
diamond
509
glass
840
of
an
cup.
capacity
1003
copper
time
thermometer
.
loss
−1
897
Figure
58
heating
heat
K
aluminium
water
equation:
capacity
Specific
/J kg
the
2.5.1
Measuring
the
heat
capacity
of
a
metal
block
It
is
surroundings.
water
.
The
specific
heating
Material
=
temperature
important
heat
from
−1
The
2.5.1
calculated
J K
energy
T
able
or
insulated
To
find
must
the
also
Method
We
can
of
heat
the
the
known
heat
mass

The
object
is
heated

The
object
is
placed

Energy
reach

is
of
the
same
gained
mass
of
energy
object.
mass
of
the
metal
block
or
water
of
(or
specific
specific
heat
heat
capacity
capacity)
of
of
water
a
solid
to
object
the
by
and
in
measured
its
from
and
recorded.
temperature
water
water
gained
The
is
and
the
the
is
recorded.
water
object
into
is
stirred
the
water
thoroughly.
until
they
both
temperature.
water
heat
temperature
using
object
transferred
the
Energy
The
the
2.5.2).
The
the
value
capacity


capacity
measured.
mixtures
use
measure
(Figure
specifi c
be
and
by
is
the
of
The
temperature
specific
water
capacity
change.
calculated
the
the
equals
object
specific
change
using
heat
heat
and
the
the
rise
capacity
the
can
energy
be
in
of
temperature,
water.
lost
by
calculated
capacity
can
be
the
using
its
calculated
mass.
Figure
WORKED
A
to
metal
of
block
140 °C.
stirred
EXAMPLE
until
water
of
The
is
mass
metal
the
3 kg
is
is
then
and
its
heated
placed
temperature
10 kg
of
the
until
into
a
water
temperature
its
temperature
container
stops
increases
of
is
the
If
the
specific
specific
heat
gain
by
heat
capacity
rising.
from
The
15 °C
heat
capacity
capacity
of
of
the
water
is
4200 J kg
and
mass
KEY
POINTS
to
−1
K
1
what
The
heat
object
metal?
energy
Energy
Measuring
rises
water
−1
20 °C.
2.5.2
2
water:
E
=
mcΔθ
=
10 kg
is
capacity,
the
C,
of
an
amount
of
heat
required
to
raise
its
H
temperature
–1
×
4200 J kg
×
5 K
=
loss
from
metal
=
capacity
of
specific
heat
capacity,
c,
metal:
c
of
a
of
energy
material
is
the
amount
210 kJ
H
heat
The
210 kJ
E
Specific
1 °C.
210 kJ
2
Energy
by
–1
K
=
required
to
raise
=
metal
mΔθ
3 kg
–1
=
SUMMARY
1
Describe
2
Copy
T
able
120 K
the
temperature
that
–1
material
by
of
1 kg
of
1 °C.
K
QUESTIONS
the
and
583 J kg
×
difference
complete
between
T
able
heat
capacity
and
specific
heat
capacity.
2.5.2.
2.5.2
Object
Mass
T
emperature
/kg
/K
change
Energy
provided
Heat
capacity
−1
water
in
a
2.0
/J
Specific
−1
/J K
/J kg
15
heat
capacity
−1
K
4200
beaker
gold
block
copper
pan
0.3
1.5
500
120
129
585
59
2.6
Changes
of
state
and
evaporation
When
LEARNING
a
further
At
the
end
should
be
of
this
able
topic
lost
you
describe
changes
compare
gains
of
a
heating
a
gas
solid.
phase).
thermal
it
the
liquid
energy
can
These
The
may
change
into
processes
names
of
also
it
may
change
a
are
the
change
liquid
called
changes
into
into
and,
if
gas.
further
changes
are
a
a
liquid.
of
shown
When
With
cooling
state
in
energy
(or
Figure
is
occurs,
changes
2.6.1.
All
of
state
the

by
into
to:
of

solid
OUTCOMES
evaporation
and
changes
although
boiling.
during
Sublimation
During
bonds
involve
is
the
the
changes
and
this
a
change
change
process
of
state
causes
the
there
in
the
in
thermal
is
which
no
a
particles
changes
in
change
solid
form
the
energy
in
or
the
substance,
temperature.
changes
directly
break
properties
of
of
to
a
gas.
inter-molecular
the
materials.
Evaporation
Evaporation
is
a
process
which
occurs
at
the
surface
of
a
liquid.
GAS
The
Vaporisation
Sublimation
or
particles
in
the
liquid
have
temperature
of
the
liquid
is
the
particles.
The
higher
a
range
related
the
to
of
kinetic
the
temperature
energies
average
is,
the
kinetic
greater
and
the
energy
the
of
average
boiling
kinetic
energy.
Condensation
The
particles
liquid.
near
However,
the
the
surface
more
are
held
energetic
in
place
particles
by
forces
may
within
escape
from
the
the
Melting
liquid
and
form
a
gas.
This
process
is
called
evaporation.
During
LIQUID
SOLID
evaporation
more
likely
the
to
particles
escape
with
from
the
the
greatest
surface.
amount
When
of
these
energy
are
fast-moving
Solidifying
or
particles
freezing
escape,
decreases.
This
the
average
decrease
in
energy
the
of
particles
average
energy
in
of
the
the
liquid
liquid
means
KEY
that
Increase
in
Decrease
internal
in
the
temperature
of
the
liquid
decreases
(Figure
2.6.2).
energy
internal
energy
Examples
Figure
2.6.1
Changes
of
state

When
you
surface
the
Air
perspire,
and
surface
the
evaporates
of
your
skin
moisture
quickly.
and
on
The
cools
your
skin
spreads
evaporation
you
takes
over
its
energy
from
down.
in

Air
and
vapour
out
by
ether
In
a
similar
way,
the
contents
the
thermal
The
earthenware
water
will
jars
in
evaporate
water
and
will
help
remove
keep
some
of
sucked
a
energy
from
the
containers.
pump

Beaker
Refrigerators
evaporation
Liquid
coating
cold.
and
air-conditioning
units
are
also
cooled
by
processes.
ether
Factors
Water
affecting
the
rate
of
evaporation
freezes
Sheet
of
wood
(any
or
There
are
insulator)

temperature
The
higher
Figure
2.6.2
The
cooling
produced
chance
the
of
ether
the
enough
water.
of
average
to
they
affect
the
rate
of
evaporation:
the
liquid.
kinetic
The
energy
of
higher
the
the
temperature
particles
and
so
the
is,
the
have
of
escaping
the
more
surface.
The
surface
area
of
the
liquid.
A
large
surface
area
will
allow
freeze
particles
60
that
is

the
factors
effect
by
evaporation
large
several
plastic
to
escape
at
a
greater
rate
and
so
evaporation
will
be
faster
.


The
humidity
saturated
with
condense
and
The
type
others
are
of
as
the
Evaporation
air
vapour
reduce
liquid.
weaker.
Comparing
and
the
Some
forces
Ether
flow.
from
holding
rate
above
some
of
particles
more
the
of
liquid
the
is
already
vapour
will
evaporation.
evaporate
the
and
are
air
liquid
overall
evaporates
boiling
the
liquids
evaporation
and
If
the
much
more
together
readily
than
in
rapidly
the
than
liquid
state
water.
boiling
often
confused
but
they
are
different
processes:

Evaporation
is
a
it
liquid
and
a
process
happens
which
can
whatever
only
the
happen
at
temperature
the
of
surface
the
of
liquid.
A
Figure
2.6.3
The
flow
speed
puddle
of

the
of
water
water
When
a
never
liquid
temperature.
the
liquid
During
will
is
reaches
heated
This
and
evaporate
is
happens
boiling
the
it
the
away
anywhere
will
liquid
a
point.
specific
turns
into
though
near
eventually
boiling
at
even
reach
Boiling
gas
a
and
bubbles
of
gas
can
be
seen
for
air
will
help
evaporation.
throughout
that
throughout
the
ACTIVITY
liquid.
whole
forming
within
the
a
little
ethanol
on
the
back
liquid.
of
your
it.
You
effect
SUMMARY
of
maximum
occurs
Pour
volume
up
temperature
100 °C.
temperature
a
the
hand
and
should
of
blow
feel
the
evaporation
over
cooling
on
your
QUESTIONS
skin.
1
A
flask
left
off
floor.
2
3
it
why,
you
Draw
ethanol
but
will
Explain
Explain
day,
of
a
will
how
after
feel
take
many
evaporate
this
in
a
hours
few
to
evaporate
minutes
if
it
is
if
the
spilt
lid
on
is
the
happens.
getting
out
of
the
sea
on
a
sunny
but
breezy
cooler.
table
stating
the
differences
between
boiling
and
evaporation.
KEY
1
POINTS
During
a
change
of
state
a
solid
can
change
into
a
liquid,
a
Figure
liquid
to
a
gas,
a
gas
to
a
liquid
or
a
liquid
to
a
2.6.4
The
but
2
It
is
possible
called
3
a
solid
to
change
to
a
gas
directly
in
a
did
has
not
evaporated
boil.
change
sublimation.
Changes
a
for
water
solid.
of
state
involve
the
gain
or
loss
of
thermal
energy
in
substance.
61
2.7
Heating,
latent
When
LEARNING
water
the
end
should
be
of
this
able
topic
water
you
more
to:
to

explain
how
to
point
measure
of
a
describe
of
a
the
cooling
substance
demonstrates
latent
and
the
begins
energy
its
temperature
to
is
the
boil,
the
being
state
when
the
rises
the
temperature
provided.
of
temperature
particles
the
This
water.
stops
increasing
additional
This
is
reaches
are
energy
because
the
100 °C
even
is
being
bonds
and
though
used
between
the
molecules
curve
how
when
this
concept
heated
to
the
are
being
convert
ice
molecular
it
altered.
reaches
forces
to
water.
A
similar
0 °C
and
and
causes
The
thing
happens
the
the
temperature
energy
ice
to
taken
stops
when
ice
in
increasing
breaks
the
inter-
melt.
of
heat.
Latent
The
as
EXAM
heat
energy
latent
separate
used
to
heat.
latent
As
change
there
the
are
state
two
of
a
substance
changes
of
state,
is
referred
there
are
to
two
heats:
TIP
Rem
embe
r
,
remai
ns
a
and
However,
substance
is

heat
heated
energy.
change
the
melting
and
OUTCOMES
gaining
At
is
cooling
chan
ge
the
tempe
rature
consta
nt

for

for
the
the
change
between
between
solid
liquid
and
and
liquid,
gas,
latent
latent
heat
heat
of
of
fusion
vaporisation
durin
g
During
of
change
cooling,
the
latent
heat
is
released
when
a
gas
changes
into
state.
a
liquid
the
or
a
liquid
temperature
energy
state
will
that
be
changes
will
stay
released
take
place
into
solid.
constant.
as
the
during
100
a
C°/erutarepmeT
Liquid
During
Also,
amount
the
exactly
of
change
the
energy
same
taken
of
state,
amount
for
changes
of
of
heating.
phase
only
A
90
Melting
80
Both
liquid
or
and
freezing
solid
70
phases
point
B
60
C
50
Solid
phase
only
40
D
30
0
5
10
15
20
25
30
35
40
Time/min
Figure
2.7.2
Between
Figure
2.7.1
The
at
temperature
100 °C
water
until
has
will
A
and
cooling
B
the
curve
for
cooling
paraffin
curve
wax
graph
shows
that
the
temperature
stay
all
of
the
turned
to
gas.
of
the
liquid
(Figure
does
not
latent
to
heat
is
decreases
Once
lose
change
temperature
energy.
wax
2.7.2).
continues
62
A
until
all
lost
the
until
reaches
energy
being
of
it
to
of
by
solid
the
the
the
wax
it
its
reaches
freezing
the
surroundings.
wax
wax.
has
In
freezing
point
(B
Note
solidified.
the
decreases
final
as
the
to
point
C)
that
the
the
During
phase
wax
(C
wax
temperature
this
to
phase,
D)
continues
the
to
lose
ACTIVITY:

Place
EXPLORING
some
HEATING
granulated
AND
COOLING
wax
Thermometer
(or
stearic
tube
and
acid)
into
suspend
a
the
Temperature
boiling
tube
in
a
Stirrer
Liquid
beaker
of
water
(Figure
2.7.3a).
Melting
point

Place
a
thermometer
into
the
Wax
wax
and
heat
the
water
while
Solid
stirring
it
to
make
temperature
is
sure
even
the
throughout.
Time

Watch
the
thermometer
to
see
Water
how
as
the
the
temperature
wax
melting
is
heated
changes
past
its
point.
Heat
At
first
will
the
temperature
increase
melting
as
point
it
wax
the
temperature
reaches
the
approaches
(Figure
the
of
its
its
2.7.3b).
melting
stops
wax
As
Figure
2.7.3
Heating
wax
and
finding
the
melting
point
point
increasing
0–100°C
and
to
the
be
wax
begins
measured
temperature

Remove
cooling
of
the
of
to
melt
accurately.
the
liquid
boiling
the
wax
it
After
wax
tube
as
instead.
all
will
from
This
of
the
begin
the
solidifies
allows
wax
to
water
has
melting
melted,
increase
and
(Figure
the
the
again.
monitor
the
2.7.4).
Boiling

Record
If
you
time
the
plot
it
a
will
temperature
graph
show
a
of
showing
cooling
the
the
wax
every
(Figure
of
the
wax
against
Wax
2.7.2).
Figure
2.7.4
Monitoring
of
SUMMARY
1
Use
the
sample
2
A
of
in
Figure
2.7.2
to
find
the
freezing
point
for
cooling
wax.
sample
of
beeswax
is
heated
until
it
melts
and
then
to
cool,
providing
the
data
in
the
POINTS
table.
1
T
able
the
wax
the
KEY
allowed
the
QUESTIONS
graph
small
tube
minute.
temperature
curve
thermometer
point
During
a
change
of
state
the
2.7.1
temperature
Time/min
1
2
3
4
5
6
7
8
9
10
11
T
emp./°C
85
80
74
69
65
62
62
58
55
52
50
a
Plot
a
cooling
b
Find
c
Would
the
melting
using
accurate
curve
a
for
point
larger
result?
the
for
does
2
sample
beeswax.
of
beeswax
3
give
a
more
a
energy
is
when
required
Latent
a
state
heat
substance
during
material
change.
Additional
changes
beeswax.
the
not
of
is
(latent
a
heat)
substance
during
heating.
released
changes
when
state
cooling.
63
2.8
Specific
To
LEARNING
compare
the
end
should

be
of
that
the
take
changes

this
able
describe
of
topic
you
As
energy
or
produced
of
state.
there
energy
This
of
different
are
required
gives
two
latent
heats:

specific
a
to
materials,
change
quantity
changes
of
the
we
known
state,
as
each
state
the
of
need
a
to
unit
find
specific
material
has
mass
The
latent
two
energy
during
required
a
change

The
1 kg
latent
of
specific
specific
a
heat
solid
of
latent
into
fusion
heat
liquid
(l )
is
of
without
the
a
energy
vaporisation
change
required
(l
)
is
in
change
of
1 kg
these
of
a
terms
liquid
can
into
be
gas
without
represented
by
energy
a
the
change
energy
the
same
provided
in
required
temperature.
equation:
(J)
E
H
–1
latent
heat
(J kg
)
=
or
mass
block
of
lead
of
its
is
heated
melting
until
point
of
it
much
energy
to
melt
the
4
=
2.3
×
10
the
specific
latent
heat
of
water
latent
heat
of
vaporisation
measure
the
specific
latent
heat
of
vaporisation
of
water
,
an
electrical
is
element
can
be
used
to
heat
a
sample
of
boiling
water
so
lead?
that
(I
m
327 °C.
additional
heating
required
(kg)
reaches
T
o
How
=
mass
Specific
300 g
l
EXAMPLE
Measuring
small
to
temperature.
v
to
specific
A
the
heat.
f
change
Both
WORKED
the
of
transfers
during
state
the
of
materials.
to:
place
calculate
heats
heat
OUTCOMES
amount
At
latent
latent
some
of
it
is
converted
into
steam
(Figure
2.8.1).
A
well-insulated
–1
J kg
container
)
needs
to
be
used
to
prevent
energy
loss
through
the
container
.
f
E
H
l
=
ACTIVITY
f
m
E
=
H
l
×

Record

Allow
the
mass
of
the
boiling
water
and
its
container.
m
f
4
=
2.3
×
10
=
6.9
×
10
by
–1
J
kg
×
the
the
water
heating
to
boil
for
several
minutes
while
being
heated
element.
0.3 kg

Find
the
energy
supplied
using
a
joulemeter
or
the
electrical
3
J
power
equation:
energy

After

Calculate
find

supplied
heating,
the
the
the
current
record
the
change
mass
Calculate
=
of
in
water
specific
×
new
mass
that
latent
p.d.
×
time
mass
of
the
of
has
the
water
boiled
heat
of
water
and
and
container.
container
to
off.
vaporisation
using
the
equation:
specific
latent
energy
heat
of
vaporisation
supplied
E
H
or
=
l
=
v
change
Specific
As
a
to
electrical
into
64
latent
sample
difficult
in
of
fi nd
mass
heat
ice
of
melts
out
element.
account
Δm
how
The
(Figure
fusion
naturally
much
following
2.8.2).
at
melts
room
as
a
temperature,
result
technique
of
takes
it
heating
the
is
more
by
natural
an
melting
Joulemeter
Beaker
in
insulating
Heater
jacket
ON
OFF
ON
To
power
IN
OUT
Top-pan
unit
balance
OFF
Figure
2.8.1
Measuring
the
specific
latent
heat
of
steam
ACTIVITY

Allow
the
minutes)
ice
to
melt
without
collected,
for
any
a
fixed
heating.
period
Record
of
time
the
(such
mass
of
as
five
water
m
1

Use
an
period
electrical
of
time
heater
and
to
melt
record
the
a
similar
mass
of
sample
water
of
ice
for
collected,
the
same
m
2

Find
the
difference
in
these
two
mass
measurements
(m
−
m
2
This
gives
provided
The

by
energy
used
in
the
the
Calculate
mass
the
of
ice
has
melted
as
a
and
calculation
the
for
specific
mass
the
latent
of
latent
heat
melted
latent
of
).
1
the
energy
heat
of
fusion
ice
as
a
result
are
heat.
of
fusion
using
energy
specific
result
heater
.
provided
the
that
the
equation:
ON
supplied
OFF
=
change
in
mass
(m
–
m
2
)
1
Joulemeter
E
H
or
l
=
f
m
–
m
2
Low-voltage
1
heater
SUMMARY
QUESTIONS
Ice
1
a
Calculate
oxygen
the
into
energy
oxygen
5
(I
=
2.1
×
10
required
gas
at
to
the
change
same
250 g
of
liquid
temperature.
–1
J kg
)
v
b
Calculate
the
energy
released
when
4.5 kg
of
lead
solidifies,
4
without
change
in
temperature.
(I
=
2.3
×
10
–1
J kg
Melted
)
ice
f
2
In
an
experiment
to
find
the
latent
heat
of
ice
as
described
in
Figure
the
activity
above,
the
following
measurements
were
2.8.2
Measuring
latent
when
the

Mass
of

Mass

Energy
of
ice
ice
ice
was
allowed
melted
melted
provided
without
when
to
to
melt
heater
heater
heater
for
=
is
five
=
on
Calculate
the
specific
heat
of
specific
ice
minutes.
5.3 g
=
KEY
15.7 g
POINT
3500 J
1
a
the
recorded
latent
heat
of
fusion
for
ice
(l
)
using
The
amount
released
or
of
energy
absorbed
during
ice
this
data.
The
agreed
a
−1
b
value
for
l
is
334 kJ kg
.
Explain
why
the
value
change
of
a
of
state
material
is
for
the
1 kg
specific
ice
obtained
by
the
experiment
is
higher
than
this
value.
latent
heat.
65
2.9
Thermal
The
LEARNING
At
the
end
should

be
in
of
this
topic
you
to:
conduction
metals
and
processes
non-metals
energy
they
part
of
a
by
process
a
perform
a
rod
the
in
an
experiment
solid
are
the
rates
of
in
called
in
fixed
is
rapidly
positions.
heated,
about
When
the
these
they
energy
positions.
gain
heat
passes
When
through
one
the
object
conduction
rod
flame
is
will
heated
become
vibrations
energy
of
using
hot.
the
a
Bunsen
The
particles
burner,
particles
will
will
cause
the
start
nearby
part
to
of
the
vibrate
particles
and
begin
to
vibrate
more.
This
process
will
to
continue
thermal
along
conduction
object
sample
The
more
to
gain
measure
a
vibrate
solid
When
rapidly.

in
OUTCOMES
able
describe
particles
conduction
the
rod
until,
eventually,
all
of
the
particles
are
vibrating
more
different
rapidly
and
the
whole
rod
has
increased
in
temperature.
The
process
materials.
of
T
able
2.9.1
Some
examples
of
thermal
passing
The
rate
The
better
energy
of
along
thermal
a
is
called
conduction
material
is
at
lattice
varies
transferring
vibration
from
material
thermal
to
energy,
material.
the
higher
its
conductivity
thermal
Material
Thermal
−1
/W m
conductivity
The
rate
conductivity
of
thermal
energy
2.9.1).
transfer
by
conduction
also
depends
on
−1
K
the
air
0.024
wood
temperature
temperature
difference
difference
between
will
increase
the
the
parts
rate
of
of
the
object.
thermal
A
large
conduction.
~0.06
Conduction
brick
0.2
glass
0.8
Metals
have
metals.
cast
(T
able
iron
This
in
metals
significantly
is
because
higher
there
is
thermal
a
conductivities
second
process
than
non-
transferring
the
55
energy
aluminium
in
metals
(Figure
2.9.1).
This
is
energy
transfer
by
free
204
electrons.
copper
‘sea’
385
of
When
diamond
Metals
free
a
contain
electrons.
metal
is
a
The
heated,
lattice
same
the
of
metal
electrons
electrons
ions
allow
rapidly
surrounded
electrical
gain
by
a
conduction.
energy
and
can
2200
pass
along
quicker
metals
the
than
are
metal
the
good
carrying
lattice
the
vibration
thermal
thermal
method
energy.
This
described
process
above
and
is
far
so
conductors.
ACTIVITY
Diamond
has
a
surprisingly
high
as
it
is
conductivity,
a
non-metal.
+
+
+
thermal
especially
+
+
Find
+
+
out
why
this
is
and
how
+
+
property
is
used
to
Ion
this
detect
+
Electron
fake
Atom
diamonds.
a
Figure
2.9.1
b
Conduction
in
a
a
metal
and
b
a
non-metal
Insulators
Poor
thermal
thermal
particle
foams,
66
conductors
conductor.
to
particle.
containing
It
is
For
lots
are
very
this
of
called
insulators.
difficult
reason
trapped
for
energy
materials,
air
are
Air
to
such
used
to
is
be
as
a
very
poor
passed
from
sponges
insulate
or
objects.
Measuring
To
rates
demonstrate
of
different
thermal
rates
of
conduction
thermal
conduction,
samples
of
the
Three
materials
can
be
heated
with
a
Bunsen
burner.
There
are
several
rods
ways
A
to
monitor
or
compare
the
rates
of
conduction:
B
C

The
as
rod
the
can
rods
be
completely
heats
up.
coated
Observing
in
the
a
thin
rate
wax
at
layer
which
that
the
melts
wax
melts
Drawing
gives
an
indication
of
how
quickly
the
thermal
energy
is
stuck
transferred.
The
far
to
underside
rod

pin
being
end
of
each
rod
can
be
coated
in
petroleum
jelly
and
of
with
a
petroleum
drawing
heats
pin
up
attached
the
pin
will
starting
heating
thermal
conductivity
(Figure
fall
until
off.
each
2.9.2).
When
Measuring
pin
falls
off
the
the
can
far
time
be
end
it
of
takes
used
to
the
rod
jelly
from
compare
the
Tripod
Comparing
of
the
material
of
each
rod.
insulators
Figure
2.9.2
The
to
The
insulating
properties
of
materials
can
be
investigated
by
time
fall
liquids
inside
identical
containers
lagged
with
these
materials
the
and
the
materials
the
temperature
can
be
used
temperature
rise
fall
to
can
lag
be
for
each
(Figure
identical
2.9.3).
containers
monitored
over
a
of
a
pin
how
heat
energy
is
and
transferred
monitoring
for
indicates
placing
quickly
hot
taken
off
along
the
rod.
Alternatively
cold
period
of
water
time.
ACTIVITY
Carry
the
out
materials
2.9.3
Comparing
SUMMARY
1
Explain
2
Why
with
need
to
1
hot
some
Thermal
test
cups
or
material.
sure
beakers
You
there
are
will
lids
evaporation.
insulators
drinks
frying
Metals
conduction
to
are
pans
sometimes
have
a
sold
copper
in
polystyrene
cups.
base?
2.9.4
have
Materials
involves
the
transfer
of
energy
from
particle.
conduction
3
to
insulating
POINTS
particle
2
the
make
prevent
Figure
KEY
of
QUESTIONS
why
do
experiment
using
lined
to
Figure
an
properties
free
electrons
much
which
more
which
quickly
conduct
poorly
transfer
than
are
is
energy
possible
classed
as
by
in
non-metals.
insulators.
67
2.10
Convection
Liquids
LEARNING
the
should

end
be
describe
in
fluids
of
this
able
topic
they
you
processes
explain
energy
can
can
explain
by
how
currents
coastal
both
fluids.
carry
thermal
within
The
energy
them.
particles
from
Because
they
place
to
the
are
composed
place
particles
as
they
can
a
travel.
currents
substance
contracts.
increases
During
in
expansion
temperature
the
particles
it
in
expands.
the
When
substance
it
cools
move
them
convection
produce
breezes
apart
contraction
in
substance
When
the
air

Because

As
For
heated
air
air
A
closer
currents.
a
substance
together
can
so
transfer
These
are
convection
decreases.
the
heat
flows
current
of
in
During
density
of
energy
by
particles
air
is
the
within
produced
used
air
air
the
sinks
less
dense
heat
as
it
particles
back
produces
both
to
is
out
further
that
energy
rises,
the
apart
become
cooler,
with
loses
a
downwards
continual
convection
convection
are
move
from
each
other
dense.
carrying
spreads
cools
process
they
particles
surrounding
air,
it.
energy
closer
and
cools.
together
and
so
the
air
currents
transparent.
show
convection
flow
and
of
the
cycle
continues.
air.
currents
in
air
These
and
two
water
can
simple
be
quite
difficult
demonstrations
can
currents.
LIQUID

Place
a
small
potassium
of
a
large
crystal
of
potassium
permanganate)
beaker
of
water
at
the
manganate( VII)
bottom
(Figure
and
(also
towards
known
one
as
side
2.10.1).
Crystal

Heat
the
current
The
rise
and
2.10.1
Demonstrating
convection
68
a
current
in
water
water
will
water
rises
by
denser.
dense
Observing
USING
the
behaviour
the
less
warm
Demonstrating
be
of
expands.
the
hot
the
The
as
move
This
example,
upwards
becomes
This
density
particles
becomes
floats
The
is
air
The

the
convection
air

it
so
processes:
and

the
substance.
these

and
increases.
producing
the
Figure
of
move
how
areas.
ACTIVITY:
are
around
be
further

move
Convection
it
transferred
to
to:
convection
and
able
When
thermal
gases
OUTCOMES
are
At
and
currents
near
upwards
with
at
it.
the
As
directly
beneath
the
crystal
and
a
convection
form.
the
the
the
other
crystal
purple
water
side
of
expands
as
colouration
reaches
the
the
beaker
it
is
heated
from
the
surface
begin
to
it
and
as
dissolving
will
sink.
the
water
crystal
spread
out,
will
cool,
ACTIVITY:

Start
USING
with
a
2.10.2).

Light
candle

Close

Hold
The
a
air
air
is
front
from
being
rising
chamber
positioned
glass
smoking
smoke
cool
hot
the
CHIMNEY
glass-fronted
(Figure
a
A
of
of
cardboard
cardboard
drawn
out
one
two
Hot
chimneys
air
Cold
chimney.
down
the
above
moves
through
chimney
the
other
downwards.
the
above
This
chimney
the
chimney.
to
is
because
replace
the
candle.
Figure
2.10.2
Demonstrating
convection
in
Air
cool
air
will
units
be
cool
denser
air
using
than
the
a
system
of
surrounding
expanding
air
air
and
so
gases.
sink
Air
warmed
land
downwards.
the
room
to
Air-conditioning
produce
a
cold
units
flow
are
of
positioned
air
towards
the
top
by
rises
of
downwards.
Sea
air
Thermal
convection
in
the
breeze
from
During
the
causes
replaced
currents
day
air
by
the
produce
land
above
cooler
the
air
breezes
heats
land
flowing
up
to
in
near
more
coast
rapidly
warm
from
the
up.
than
The
above
(Figure
warm
rise
cooler
the
warm
the
sea.
sea
and
Convection
air
the
land
flows
currents
temperatures
cools.
from
within
across
the
cooler
flowing
air
At
the
This
the
land
causes
oceans
to
the
air
above
rises
night
the
have
a
to
replace
warm
air
and
and
the
is
sea
Figure
2.10.3
A
cool
sea
breeze
the
sea
flows
in
during
to
the
and
to
sea
2.10.3).
from
remains
due
the
atmosphere
in
Convection
this
a
current
conditioning
Air-conditioning
The
air
panel.
piece
the
under
with
day.
sea.
significant
effect
on
the
globe.
ACTIVITY
SUMMARY
Convection
currents
responsible
for
the
continents
surface
Explain
why,
during
a
fire
in
a
room,
you
should
crawl
2
floor
How
KEY
can
to
a
make
hot-air
your
of
this
the
Find
out
works.
escape.
balloon
control
its
height?
POINTS
Convection
can
only
occur
in
fluids
as
it
involves
of
particles
from
place
to
fluids
in
density
caused
by
rise
place.
fluids
,
Changes
TIP
the
Ho t
movement
2
Earth.
process
EXAM
1
the
across
across
how
the
movement
QUESTIONS
of
1
the
are
expansion
result
in
convection
Never
e.g.
say
ho t
that
abov
e
air
co ld
rises
.
heat
rises
.
currents.
69
2.11
Infra-red
Thermal
LEARNING
energy
the
end
should
be
of
this
able
topic
describe
affect
objects
red
the
the
you
properties
to:
factors
rate
as
of
they
(a
is
a
transferred
part
longer
of
of
than
visible
the
by
infra-red
radiation
electromagnetic
(IR
visible
light
light.
including
IR
the
spectrum
radiation
ability
to
shares
travel
with
many
a
of
through
the
empty
vacuum).
that
cooling
radiate
All
of
infra-
objects
their
are
constantly
surfaces.
This
gives
emitting
three
and
absorbing
possible
IR
conditions
radiation
for
an
from
object:
radiation


This
wavelength
space

be
OUTCOMES
radiation).
At
can
radiation
describe
affect
the
the
objects
factors
rate
as
of
they
that
heating
absorb
at
of
a
up
greater
sunlight
–
an
rate
will
object
than
warm
it
up
will
is
warm
emitting
up
it.
if
A
it
is
cold
absorbing
drink
IR
radiation
placed
in
direct
rapidly.
infra
red
Warming
Cooling
down
–
an
object
cools
down
when
it
is
emitting
more
IR
radiation.
radiation
food

will
and
See
is
absorbing
cool
temperature
are
will
the
stay
–
same
at
a
to
if
from
room
the
then
steady
surroundings.
Freshly
cooked
temperature.
rate
the
its
of
absorption
object
will
temperature.
not
and
gain
Most
the
or
rate
lose
objects
in
a
of
energy
room
TIP
will
3.3
abou
t
so
it
gradually
Constant
emission
EXAM
than
to
the
spectru
m
be
each
find
out
at
‘room
temperature’.
They
are
at
the
same
temperature
as
other.
more
electr
omag
ne tic
and
absorp
tion
the
and
Factors
ideas
affecting
the
rate
of
heating
or
cooling
of
emiss
ion.
T
emperature
A
hot
object
means
that
objects.
If
you
see
will
will
very
you
emit
hot
far
monitor
that
more
objects
the
the
IR
lose
radiation
energy
temperature
temperature
drops
at
then
a
of
a
cool
greater
a
cooling
more
one.
rate
drink
rapidly
at
This
than
cooler
then
the
start
of
Incident
the
experiment
than
later
on.
Eventually
the
drink
will
reach
room
radiation
temperature
Reflection
stop
cooling.
and
absorption
here
Properties
The
an
Smooth
and
of
the
absorption
object
and
or
so
surface
emission
the
of
IR
properties
radiation
of
the
happens
surface
are
at
very
the
surface
of
important:
surface

The
surface
energy
Incident

Scattering
The
to
area
of
escape
colour
of
or
the
the
be
object.
A
larger
absorbed
surface.
Dark
more
surface
area
will
allow
rapidly.
surfaces
are
much
better
absorbers
and
radiation
absorption
here
and
emitters
into
bright
The
Rough
a
2.11.1
A
rough
larger
so
is
surface
overall
able
infra-red
70
larger
to
has
a
surface
absorb
radiation.
area
more
radiation
of
2.11.1).
than
wearing
clothes
the
surface
surface
(Figure
Figure
Your
roughness
have
IR
sunlight
immediately.

of
dark
start
surface.
area
white
to
A
when
surfaces.
clothes
feel
you
If
will
you
step
notice
out
this
effect
hot.
rougher
surface
compared
to
a
will
effectively
smooth
surface
ACTIVITY
A
Leslie’s
different
poured
same

cube
is
colours
into
the
a
metal
or
with
container
different
container
and
all
with
the
textures.
of
the
surfaces
Boiling
sides
painted
water
rapidly
is
reach
the
temperature.
Place
a
temperature
sensor
(or
the
back
of
your
hand)
close
to
EXAM
the
different
being
surfaces
to
measure
(or
feel)
the
thermal
radiated.
T
ry
You
TIP
energy
should
find
that
the
dark
or
rough
surfaces
emit
to
remem
ber
dark
er
thermal
radiation
than
the
white
and
shiny
colou
rs
one
experiments
side
painted
Investigating
To
investigate
place
hot
colours,
of
each
for
and
similar
coloured
Both
cool
of
a
how
recorded
and
the
cooling
and
also
the
placed
up
slows
room
the
the
are
the
plates
tempe
rature
with
of
with
2.11.2).
a
of
patterns
can
IR
The
period
the
water,
materials
1
be
used
radiation.
sunlight
or
near
can
temperature
Stopclock
twenty
in
cooling.
to
The
to
you
a
different
radiant
monitored.
beakers
than
difference
with
the
in
the
silvered
black
surfaces
surface.
temperature
The
between
rate
the
decreases.
POINTS
All
2.11.2
SUMMARY
objects
are
quick
ly.
different
Figure
KEY
chan
ge
more
shiny.
painted
over
absorb
rapidly
left
been
compare
cold
rises
metal
cooling
(Figure
direct
that
more
as
in
other
minute
surfaces
with
surfa
ces
heating
have
to
very
out
the
black
every
using
confirm
heat
that
and
temperature
experiments
or
are
and
plotted
different
beakers
down
water
silver
is
and
affecting
beakers
graph
carried
black
factors
into
is
be
cooling
experiment,
investigate
heater
matt
example
beaker
minutes
A
the
water
can
and
surfaces.
rough
er
Similar
that
more
constantly
absorbing
or
emitting
infra-red
Investigating
the
colour
the
rate
of
of
the
a
effect
surface
of
on
cooling
QUESTIONS
(IR)
1
In
many
tropical
countries
radiation.
buildings
light
2
The
hotter
an
object
is
the
more
IR
radiation
it
The
temperature
of
dark
coloured
objects
changes
rapidly
help
are
good
emitters
and
absorbers
of
IR
The
temperature
of
silver
coloured
objects
changes
slowly
are
poor
emitters
and
absorbers
of
IR
Rough
surfaces
radiation
than
are
better
smooth
emitters
and
to
cool
warm
these
keep
the
during
the
day
during
the
night?
In
the
Arctic,
polar
bears
are
radiation.
white.
5
in
as
2
they
do
radiation.
and
4
How
as
building
they
painted
emits.
colours
3
are
colours.
absorbers
of
them
IR
How
keep
does
this
help
warm?
surfaces.
3
In
Antarctica,
huddle
numbers.
them
penguins
together
How
keep
in
large
does
this
help
warm?
71
2.12
Applying
energy
thermal
transfer
principles
Understanding
LEARNING
allows
At
the
should
end
be
of
this
able
topic
us
heating
you
large
to:
to
describe
how
transfer
of
can
or
be
used
increase
energy
of
we
of
objects.
thermal
need
to
or
thermal
energy
decrease
Sometimes
energy
prevent
into
the
the
loss
we
the
transfer
need
rates
to
surroundings
or
gain
of
of
dispose
quickly
thermal
of
and
energy.
in
a
flasks
to
the
flow
vacuum
wide
flask
is
designed
to
prevent
as
much
thermal
energy
of
as
possible.
To
do
this
it
has
features
that
reduce
conduction,
range
convection,
of
cause
increase
energy
transfer
heat
which
to
the
thermal
A
reduce
cooling
amounts
Vacuum
of
devices
an
understanding
methods
processes
design
and
sometimes

the
OUTCOMES
radiation
and
evaporation
processes
(Figure
2.12.1).
circumstances.

The
main
with
no
a
particles
thermal
Plastic
chamber
vacuum
there
energy
transferred
plastic)
Plastic
constructed
can
be
between
the
two
no
of
glass
layers.
conduction
the
layers.
(a
As
very
the
or
poor
conductor)
vacuum
convection
Thermal
energy
contains
to
can
transfer
be
cap
Double-walled
(or
is
between
around
the
glass
layer
by
conduction
but
this
is
a
very
glass
slow
container
protective

The
process.
inside
surfaces
of
the
glass
layers
are
coated
in
silver
to
reduce
cover
radiation.
Hot
or
cold
Sponge
The
surfaces
are
very
poor
emitters
and
absorbers
of
liquid
radiation
so
there
A
plastic
is
very
little
transfer
of
energy
between
them.
pad

hollow
cap
is
used
to
prevent
evaporation.
(protection)
Inside
surfaces
silvered
to
Solar
stop
water
heaters
radiation
Vacuum
prevents
Many
houses
heat
water
using
solar
energy.
Cool
water
is
either
conduction and
pumped
or
driven
by
convection
currents
through
pipes
in
panels
convection
on
Plastic
for
the
2.12.1
A
absorb
support
vacuum
(Figure
energy
Car
The
the
passing
for
are
heaters
used
keep
the
night.
72
pipes
are
painted
black
so
that
sunlight
and
this
energy
is
transferred
they
to
the
them.
of
for
can
heat
water
.
washing
house
large
They
or
warm
at
cooling
radiators
engine
fuel
is
in
a
car
burnt.
If
produces
this
engine
would
parts
prevent
engine.
front
of
the
the
radiator
the
air.
to
the
this,
conduction
amounts
the
through
of
the
Solar
from
temperature
To
2.12.2
The
flask
Designs
Figure
2.12.2).
spring
water
Figure
roof
The
and
car
engine
soon
water
water
is
is
and
large
were
would
cause
2.12.3).
thermal
through
of
As
the
energy
to
a
car
is
thermal
build
up
then
when
the
of
the
up.
which
thermal
radiator
moves,
energy
Expansion
seize
pipes
the
through
of
to
rapidly.
engine
some
pumped
amount
allowed
increase
the
pumped
absorbs
then
(Figure
pipes
a
energy
energy
through
by
mounted
air
transferred
pass
travels
from
on
the
between
the
water
to
Cooling
The
panels
back
energy
Heat
panels
taken
on
from
refrigerators
refrigerators
the
inside
to
are
be
painted
radiated
black
away
to
allow
heat
quickly.
sinks
Microprocessors
during
their
damage
sure
on
the
that
can
produce
operation.
processor
this
This
if
happens,
it
a
very
large
energy
is
not
heat
will
amounts
reduce
transferred
sink
is
of
the
away
mounted
heat
energy
efficiency
rapidly.
on
the
top
or
To
of
even
make
the
Figure
microprocessor
(Figure
2.12.4).
A
highly
conductive
‘thermal
paste’
2.12.3
In
a
car
radiator,
increase
used
as
the
glue
between
the
processor
and
heat
sink.
The
heat
designed
to
have
many
fins
so
that
the
heat
energy
can
be
both
by
radiated
The
The
convection
Earth
the
a
by
process,
balance
However,
for
more
heat
of
with
fans)
and
area
fins
and
also
to
be
painted
increase
the
black
rate
of
The
Earth
activity
such
as
to
be
ocean
trapped
as
light
the
longer
back
to
at
short
surface
and
tends
remained
and
atmosphere.
wavelength
the
dioxide
effect,
energy
to
of
methane.
maintain
constant
years.
burning
and
gases
visible
carbon
has
this
through
energy
as
and
as
reflected
such
thousand
greenhouse
and
this
is
warming
Sun
passes
greenhouse
deforestation
energy
atmospheric
this
the
arrives
which
gases
the
2.12.5).
human
amount
as
of
global
by
energy
re-emits
Some
several
production,
radiated
Sun’s
Earth
known
and
radiation
greenhouse
(Figure
temperature
the
the
radiation.
Earth
crop
The
infra-red
of
effect
energy
planet.
surface
infra-red
The
assisted
pipes
emission.
absorbs
wavelength
the
(sometimes
away.
greenhouse
warms
The
currents
surface
carried
may
away
the
sink
and
is
fins
is
fossil
keeping
in
the
and
fuels,
livestock
atmosphere.
results
in
an
increased
is
Figure
2.12.4
A
This
overall
heat
sink
mounted
on
a
microprocessor
increasing
causes
increase
in
temperatures.
SUMMARY
1
Describe
QUESTIONS
how
a
vacuum
flask
Sun
can
Some
back
Heat
from
passes
the
heat
into
keep
contents
cold.
escapes
space
2
How
can
warming
Sun
Heat
is
back
to
the
be
effects
of
global
slowed?
reflected
through
Earth
by
atmosphere
'greenhouse
C0
in
gases'
air
Earth
2
Heat
is
back
from
KEY
POINT
radiated
1
Careful
2.12.5
The
increase
in
selection
of
materials
Earth
can
Figure
its
greenhouse
gases
may
lead
to
catastrophic
climate
be
used
to
control
heat
flow.
change.
73
Section
SECTION
1
2:
During
2
Practice
an
Practice
exam
investigation
exam
questions
questions
into
cooling
by
5
Compare
the
behaviour
and
spacing
of
the
3
evaporation,
into
each
different
and
of
20 cm
five
of
circular
diameters.
ethanol
ethanol
was
was
beakers
The
mass
measured
of
with
placed
that
the
a
particles
had
concepts
beakers
fluidity
The
ethanol
samples
were
allowed
for
30 minutes
and
of
Describe
the
beakers
was
recorded
4
Diameter/cm
5.5
explain
the
then
the
the
three
the
and
gases.
Use
compressibility
states
of
these
and
matter.
changes
in
particle
behaviour
and
changes
in
energy
during
the
following
mass
changes
of
to
liquids
to
the
evaporate
solids,
top-pan
6
balance.
in
of
state:
again.
6
7
a
from
solid
to
b
from
liquid
liquid
10
to
gas.
2
Area/cm
7
Start
75.5
mass/g
95.5
121.0
141.0
A
metal
block
strongly
End
67.9
mass/g
81.2
104.0
117.9
The
133.3
until
block
is
containing
Change
mass
its
0.8 kg
is
temperature
heated
then
placed
4.0 kg
of
into
cold
reaches
a
is
stirred
stops
Calculate
the
surface
area
of
each
of
rises
the
until
rising.
from
the
water
The
10 °C
temperature
and
temperature
to
19 °C.
of
of
(The
the
Calculate
the
mass
loss
for
each
of
the
of
water
the
is
a
Calculate
b
Calculate
the
c
State
heat
the
water
the
4200 J kg
water
heat
−1
K
temperature
water
specific
−1
capacity
beakers.
b
200 °C.
bucket
in
mass/g
a
of
180.5
.)
rise
of
the
water
.
beakers.
c
Plot
the
a
graph
surface
comparing
area
of
the
the
mass
loss
energy
gained
by
the
water.
and
the
energy
loss
of
the
metal
beakers.
block.
d
Describe
the
mathematical
relationship
d
between
the
surface
area
and
the
rate
Calculate
the
specific
heat
capacity
of
the
of
metal.
evaporation
for
ethanol.
8
e
Use
the
graph
to
find
the
rate
T
wo
metal
from
evaporation
per
centimetre
plates
squared
for
ethanol
during
the
an
electrical
Describe
can
3
be
how
a
liquid-in-glass
a
thermometer
and
period
of
following
calibrated.
Describe
explain
the
key
features
of
thermometer
as
shown
in
equal
distance
heater.
and
the
One
other
plate
matt
is
shiny,
black.
the
of
five
each
plate
minutes
results
is
as
recorded
The
shown
in
over
the
table.
a
Time/min
clinical
an
experiment.
temperature
2
placed
per
silver-coloured
minute
are
of
0
1
2
3
4
5
6
7
8
9
10
30
40
48
55
61
66
70
74
77
80
82
30
45
58
65
70
75
78
79
81
82
82
diagram.
T
emperature
of
shiny
Cross-section
plate/°C
T
emperature
35
36
37
38
39
40
41
42
of
black
plate/°C
4
Copy
and
complete
temperatures
this
between
table
converting
degrees
Celsius
and
a
kelvin.
Plot
graph
comparing
temperature
b
0
Celsius/°C
100
−50
Describe
0
of
and
rise
explain
the
pattern
temperatures.
Why
do
the
plates
temperature?
in
plates.
234
c
74
the
the
−127
in
Kelvin/K
a
stop
rising
in
in
the
rise
9
Liquid
nitrogen
systems,
state
from
nitrogen
a
is
energy
heat
of
liquid
as
it
10
in
rapid
energy
to
a
to
it
How
absorb
for
cooling
when
gas.
changes
vaporisation
5
×
used
required
heat
2.0
is
absorbing
much
500 kJ
state?
liquid
13
changes
liquid
of
(The
is
students
evaporation
and
ether.
fume
latent
nitrogen
Some
into
of
much
ice
with
energy
a
is
required
starting
to
convert
temperature
of
students
rectangular
pour
trays
out
the
in
a
liquids
measuring
3.0 kg
of
steam
with
a
final
is
the
surface
area
of
the
liquids
in
trays?
3.0 kg
−5 °C
students
measure
the
mass
of
the
liquids
temperature
and
of
carried
of
ethanol
5 cm.
What
The
into
is
rate
water,
.)
the
How
The
the
liquids:
experiment
cupboard.
by
investigating
different
−1
J kg
a
10
The
identical
4 cm
are
of
trays
at
the
start
of
the
experiment
and
105 °C?
after
−1

Specific
heat
capacity
of
ice:

Specific
heat
capacity
of
water:
−1
4181 J kg
2100 J kg
10
minutes.
Their
results
are
shown
in
−1
K
the
table.
−1
Starting
K
Change
Rate
in
evaporation
of
mass/g
/g min
End
Liquid
mass/g
mass/g
−1

Specific
heat
−1
2080 J kg

Specific
capacity

×
K
latent
10
Specific
heat
of
11
Describe
fusion
for
water
14.4
14.2
ethanol
13.4
12.4
ether
17.8
12.6
ice:
−1
J kg
latent
heat
of
6
water:
steam:
−1
5
3.3
of
2.3
×
how
a
10
vaporisation
for
−1
J kg
group
of
students
could
b
determine
the
specific
latent
heat
Which
liquid
has
evaporated
at
the
fastest
of
rate?
vaporisation
of
ethanol.
You
must
include:
2
c

the
equipment

an
assessment

an
explanation
What
for
of
the
risks
of
the
measurements
each
the
end
the
of
of
that
of
evaporation
per
cm
the
liquids?
the
they
experiment
did
not
turn
the
on
students
the
fume
required.
cupboard
Explain
rate
and
notice
12
the
involved
At
calculations
is
required
following
in
terms
of
infra-red
extractor
fan
as
they
were
supposed
to.
radiation:
d
a
b
Some
firefi ghters
when
entering
Solar
water
wear
burning
heaters
on
silvered
clothing
In
what
way
different
if
would
the
fan
the
had
results
been
have
turned
been
on?
buildings.
roofs
are
painted
black.
c
Dark-coloured
washing
line
clothing
than
dries
faster
light-coloured
on
a
clothing.
75
3
Waves
3.1
Wave
Wave
LEARNING
motion
the
end
should

be
of
this
able
describe
topic
you
caused
of
by
describe
the
between
give
a
Wave
differences
of
and
the
waves
examples
of
oscillation
or
a
series
in
roun
d
can
will
the
pulse
be
demonstrated
produce
of
of
spring
the
is
a
end
the
of
is
coils
with
vibrations
will
a
until
type
the
of
coils
along
long
allow
spring
generated.
the
stretched
wave
The
pulse
slightly
are
the
Single
left,
why
in
us
is
carry
A
hand
transverse
A
Vibrations
of
the
describe
in
spring.
wave
one
part
Observing
motion.
motion
one
is
of
the
sideways
the
end
in
end
spring
and
The
(Figure
in
and
the
once,
out
a
length
3.1.1a).
and
spring
together
back
along
(Figure
pushed
produced.
closer
turn
If
the
rapidly
has
regions
these
regions
3.1.1b).
movement:
movement
Fixed
end
Fixed
end
pulse
hand
then
3.1.1
movement:
Pulse
pull
Continuous
ACTIVITY
continues
train
a
table
comparing
of
transverse
longitudinal
different
Research
these
them
category
by
of
over
the
a
of
along
produced
A
the
if
the
continuous
spring.
The
source
series
of
particles
of
the
pulses
vibration
form
oscillate
in
a
a
wave
a
period
of
time,
repeating
the
same
regular
pattern.
of
waves
There
are
two
classes
of
waves:
transverse
and
longitudinal
and
correct
describing
the
spring
range
Transverse
waves
the
T
ransverse
motion
a
waves
waves.
types
into
in
waves.
produce
types
are
oscillate.
moving
Classes
Earthquakes
motion
the
motion
properties
Compression
waves
waves
to
movement
pulse
Wave
Continuous
waves
form
when
the
oscillations
of
the
particles
are
particles.
perpendicular
transfer).
to
76
rest
right
longitudinal
Figure
place
to
move
reaches
with
Rarefaction
of
a
energ
y.
b

producing
matter
,
push,
and
oscillations
springs.
the
moved
coils
compressed
length
then
Single
Draw
the
pulse
wave
fixed
T
hat’s
don’
t
of
wave
springs
wave
a

without
single
train.
Pulse
only
place
a
pulses
where
parti
cles
in
When
move
wave
s
to
be
waves.
TIP
positio
ns.
wave
behaviour
another
T
he
single
spring
spring
oscil
late
place
may
transverse
longitudinal
EXAM
a
motion
the
Wave
and
from
There
medium
transverse
longitudinal

energy
(matter).
waves
Waves
in
material
progressive
to:
how
propagate

transfers
OUTCOMES
transfer
At
motion
The
oscillate
to
the
direction
movement
and
this
of
of
one
oscillation
is
propagation
particle
passed
causes
along
(direction
the
the
of
the
energy
neighbouring
wave
(Figure
particle
3.1.2).
Wave
Left
movement
Crest
To
fixed
end
Right
Hand
Figure
Ripples
causes
Light
repeated
regularly
3.1.2
A
on
the
the
waves
surface
and
Longitudinal
In
example
the
waves
The
forcing
oscillations
and
to
propagation.
positions
water
to
of
a
are
transverse
oscillate
from
vertically
the
direction
fields
in
A
while
disturbance
the
water
source.
transverse
magnetic
waves.
wave.
which
which
the
Light
vibrate
wave
waves
at
consist
right
of
angles
to
propagates.
waves
longitudinal
of
of
horizontally
electric
other
wave
molecules
out
another
oscillating
each
transverse
water
spread
is
Trough
movement
the
their
(Figure
particles
particles
oscillate
move
neighbours
back
to
parallel
and
follow
forth
the
to
the
about
same
direction
their
pattern
rest
of
3.1.3).
Figure
Wave
1
Hand
To
movement
tank
ripple
fixed
A
3.1.3
A
longitudinal
waves
are
wave
single
oscillation
a
wave
wave
Progressive
motion
with
ripple
(Figure
the
when
The
of
3.1.4).
water
,
a
A
of
when
the
the
to
motor
wave
of
the
waves
investigate
causes
parallel
‘dipper’
propagation
see
used
producing
round
crests
wave
SUMMARY
Figure
waves
is
a
horizontal
plane
used
in
transverse
waves.
place
of
form
wavefronts
wave.
Observation
reflect,
change
to
Circular
the
and
of
speed
wave
beam
or
motion
dip
these
in
waves
horizontal
the
train
consist
produced
of
by
oscillations.
Transverse
water
and
are
out
produced
of
oscillate
generated
to
beam.
travel
in
wavefronts
change
in
the
waves
when
are
particles
perpendicularly
direction
of
wave
propagation.
the
direction
allows
us
4
Longitudinal
to
produced
direction.
oscillate
waves
when
of
are
particles
parallel
direction
1
which
a
tanks
3
are
through
longitudinal.
regular
Observing
tanks
will
pulse
medium.
a
Ripple
in
regularly
2
Sound
waves
end
propagates
Figure
plane
POINTS
produce
repeated
and
a
Compressions
Rarefactions
Pull
Circular
movement
KEY
Push
3.1.4
to
the
propagation.
QUESTIONS
3.1.5
shows
a
wave
pulse
in
a
rope.
a
Which
type
b
Redraw
of
wave
is
shown?
−1
The
pulse
is
traveling
at
40 cm s
of
2
cm
Figure
10
20
30
40
50
60
70
80
90
100
the
Sketch
the
would
see
centre
of
the
diagram
pulse
a
0.5
pattern
if
a
of
pebble
calm
showing
second
wavefronts
were
the
position
later.
that
dropped
you
into
the
pond.
3.1.5
77
3.2
Describing
Progressive
LEARNING
At
the
end
should

be
can
of
this
topic

A
displacement–position

A
displacement–time
waves
use
period
the
in
a
and
amplitude
A
wave
range
interpret
position
time
kinds
of
graph:
graph
graph
displacement–position
displacement–position
speed
of
in
graphs
a
wave
at
a
graph
fixed
represents
time
the
during
its
shown
at
position
of
movement.
all
The
of
the
positions
equation
a
large
number
of
particles
are
a
single
instant,
like
a
contexts
snapshot

different
terms
of
in
two
wavelength,
particles

by
to:
frequency,
speed,
represented
you
Understanding
of
be
OUTCOMES
able
describe
waves
waves
photograph
(Figure
3.2.1).
displacement–
and
graphs
displacement–
for
waves.
selcitrap
tnemecalpsiD
Wavelength
λ
fo
a
Position
B
A
C
Mean
or
Wavelength
along
wavetrain
λ
a
rest
position
Wavelength
Figure
The
and
the
metres.
and
In
another
(having
This
the
means
wavelength
EXAM
For
unit
T
he
is
that
the
no t
hertz
same
is
the
as
the
of
that
it
a
wave
is
a
is
wavelength
that
is
of
the
is
exactly
displacement
all
the
distance,
troughs
fixed
distance
the
the
at
and
a
distance
the
a
between
wavelength
same
moving
on
time
in
one
is
between
point
the
transverse
in
its
same
wave
wave
measured
a
particle
motion
direction).
are
also
one
apart.
waves
adjacent
The
amplitude,
can
have
crest
the
wavelength
compressions
or
is
a
measure
of
the
distance
rarefactions.
a
distan
ce
to
a
from
a,
the
a
its
of
rest
a
wave
is
the
depth
greater
of
(undisturbed)
maximum
a
trough.
distance
In
from
position.
displacement
high
their
It
is
amplitude
rest
the
height
a
particle
waves
the
of
a
particles
position.
um
from
of
or
oscillate
the
parti
cle,
from
Understanding
displacement–time
graphs
a
A
displacement–time
graph
shows
the
behaviour
of
a
single
particle
troug
h.
over
a
period
changes
particle
78
the
particle
same
of
As
at
the
a
maxim
positio
n
peak
fact,
longitudinal
between
−1
displa
cemen
t
rest
λ,
next.
graph
s
ampl
itude
wave
displacement–position
TIP
Rem
embe
r
(Hz)
A
wavelength,
crest
in
3.2.1
λ
as
at
a
of
time.
wave
point
C
It
shows
passes.
from
how
Figure
the
the
3.2.2
displacement
represents
displacement–position
the
of
the
particle
motion
graph.
of
a
elcitrap
tnemecalpsiD
Period
WORKED
EXAMPLES
a
the
T
What
is
water
wavelength
wave
with
a
of
a
frequency
fo
a
of
5.0 Hz
and
a
speed
of
−1
25 cm s
Time
Period
or
?
a
Mean
T
Original
rest
equation:
position
v
=
fλ
Transpose
Figure
3.2.2
A
displacement–time
the
equation:
graph
v
λ
=
f
The
period,
T,
of
a
wave
is
the
length
of
time
taken
for
a
particle
to
Substitute
complete
one
full
oscillation.
The
particle
moves
from
the
rest
in
values:
position
–1
to
maximum
positive
displacement
back
through
the
rest
position
to
25 cm s
the
λ
maximum
The
negative
frequency,
f,
displacement
of
a
wave
is
and
the
then
back
number
of
to
the
rest
=
position.
oscillations
per
second.
5.0 Hz
Answer:
−1
Frequency
has
the
unit
hertz
(Hz)
which
is
identical
to
the
unit
s
λ
Period
and
frequency
are
related
by
the
b
1
period
1
=
=
5.0 cm
equation:
or
T
What
of
a
is
the
light
frequency
wave
which
=
8
frequency
travels
f
and
Therefore
the
greater
the
frequency
of
the
wave
the
shorter
at
has
3.00
a
×
10
−1
m s
wavelength
of
the
−7
4.00
period
will
10
m?
be.
v
Wave
×
speed
=
fλ
v
(v)
f
=
λ
Different
waves
travel
at
different
speeds.
For
example,
a
water
wave
−1
may
travel
at
5.00 m s
8
3.00
×
8
whereas
a
light
wave
may
be
travelling
at
3.00
f
−1
10
m s
.
The
speed
of
a
wave
is
related
to
the
frequency
×
by
the
−1
m s
and
−7
4.00
wavelength
10
=
×
10
m
equation:
14
f
wave
SUMMARY
speed
=
frequency
×
wavelength
or
v
=
A
sound
this
wave
has
a
period
of
0.04 s.
What
is
the
frequency
of
1
wave?
Sketch
a
×
The
by
speed
the
displacement–time
graph
for
a
particle
at
point
B
of
3.2.1
if
the
frequency
of
the
wave
is
Copy
T
able
3.2.1.
Then
calculate
the
speed
in.
You
must
include
the
missing
appropriate
values
and
A
can
500 Hz
0.2 m
3
a
be
A
the
particles
fixed

=
(v
frequency
=
×
fλ)
displacement–position
the
f
given
used
to
units.
3.2.1
v
is
fill
represent
T
able
wave
2 Hz.
graph
them
a
in
2
3
Hz
equation
wavelength
Figure
10
POINTS
wave
2
7.50
QUESTIONS
KEY
1
=
fλ
positions
in
a
wave
a
time.
displacement–time
can
of
at
be
used
to
graph
represent
the
−1
b
340 m s
c
3.00
3.5 kHz
8
×
10
motion
−1
m s
−3
5.00
×
10
m
(or
of
point)
period
of
a
in
single
a
particle
wave
over
a
time.
79
3.3
Electromagnetic
Visible
LEARNING
the
end
should
be

the
state
is
of
this
able
topic
very
the
you
small
properties
which
on
their
differentiate
by
waves
of
the
electromagnetic
whole
radiation
electromagnetic
but
it
only
spectrum
wavelengths
or
are
how
grouped
they
are
spectrum.
forms
into
six
Waves
major
produced
in
regions
(Figure
3.3.1).
properties
of
electromagnetic
radiation
share
electromagnetic
their
of
all
Common
waves
form
part
electromagnetic
based
to:
electromagnetic

a
OUTCOMES
a
At
light
waves
wavelength
or
All
electromagnetic
and
(EM)
radiations
share
some
common
properties
behaviours:
frequency


specify
sources
and
uses
EM
radiation
travels
as
a
transverse
wave.
for
8

each
of
the
regions
of
EM
radiation
parts
electromagnetic
travels
at
−1
3.00
×
10
m s
travel
at
different
in
a
vacuum.
Different
the
of
the
spectrum
speeds
in
other
materials.
spectrum.

The
wave
does
The
wave
motion
and
no
not
particles
require
consists
are
a
of
medium
(material)
oscillating
electric
to
pass
and
through.
magnetic
fields
required.
ACTIVITY
The
in

Produce
about
a
the
summary
sources,
T
able
detectors
and
uses
of
electromagnetic
waves
are
shown
3.3.1.
poster
properties
and
Ionisation
uses
of
waves.
electromagnetic
Make
include
sure
some
wavelengths
that
you
examples
and
of
the
frequencies
involved.

Find
of
out
the
used
how
EM
for
systems
different
spectrum
Some
This
forms
means
of
EM
that
radiation
electrons
charged
particles
damage
living
called
tissue,
carry
are
ions.
enough
removed
These
causing
ions
mutations
are
or
the
to
ionise
atoms
highly
atoms.
which
reactive
become
and
can
cancers.
parts
can
be
communication
including
subcategories
of
SUMMARY
the
radio
QUESTIONS
waves.
1
What
the
2
is
EM
Copy
relationship
3.3.2.
calculate
identify
T
able
the
spectrum
T
able
given,
which
and
between
the
Then,
the
region
for
of
the
damage
each
missing
the
it
of
frequency
can
the
frequency
EM
cause
/m
a
8.8
×
10
b
1.4
×
10
7
−8
c
2.2
×
10
d
1.3
×
10
−2
a
part
living
wavelength
spectrum
the
Region
15
of
to
electromagnetic
or
3.3.2
f/Hz
80
energy
from
wave
of
cells?
waves
and
then
belongs
in.
T
able
3.3.1
Sources,
detectors
and
uses
of
electromagnetic
waves
Frequency /
Sources
Uses
hertz
Radio
waves
Electron
movements
Communications
22
10
in
transmitter
circuits
such
as
radio
γ-rays
or
–13
10
21
of
TV
and
radio
television.
10
–12
systems.
Microwaves
are
10
used
=
1 pm
20
to
cook
food
as
their
10
–11
X-rays
10
energy
is
absorbed
19
10
easily
by
water
and
–10
10
fat
molecules.
18
10
–9
Infra-red
Any
warm
or
hot
Infra-red
10
cameras
=
1 nm
17
10
radiation
object.
(often
used
for
–8
10
The
higher
the
seeing
during
night-
UV
16
10
temperature
of
the
time).
–7
10
object
the
shorter
IR
thermometers
to
Violet
15
light
0.4
μm
10
VISIBLE
the
wavelength.
measure
temperature
–6
10
=
1 μm
14
without
contact.
Red
10
light
0.7 μm
–5
10
Visible
light
Very
hot
objects.
Photography.
13
10
Some
chemical
Lasers.
–4
IR
reactions.
10
12
Sight.
1 THz =10
–3
Ultraviolet
Very
hot
objects
Forensic
10
science.
=
1 mm
11
10
light
such
as
the
Sun.
Chemical
lamps
Sterilisation
analysis.
–2
10
Fluorescent
Micro
of
10
10
containing
mercury.
waves
equipment.
–1
10
UHF
9
X-rays
X-ray
tubes
which
Forming
images
of
1 GHz = 10
TV
1
propel
fast
electrons
bones
in
the
=
1 metre
body.
VHF
8
10
into
metal
blocks.
High-energy
radio
X-rays
Short-
can
be
used
to
find
in
other
6
materials.
1 MHz = 10
OIDAR
10
damage
10
7
wave
radio
2
10
Med.-
wave
radio
3
10
Gamma
rays
Decay
of
radioactive
Cancer
=
1 km
treatment
5
10
materials.
(radiotherapy).
Nuclear
Gamma
Long4
wave
explosions.
emitters
are
4
10
radio
10
Gamma
ray
bursts
used
as
radioactive
5
10
3
from
cosmic
events
tracers
in
medicine
1 kHz = 10
Wavelength /
such
as
black
formation
of
or
holes.
other
applications.
Sterilisation
metre
of
Figure
equipment
or
3.3.1
The
electromagnetic
spectrum
some
foods.
KEY
1
POINTS
All
electromagnetic
vacuum
2
waves
travel
at
the
same
speed
in
a
space).
Electromagnetic
(and
3
(empty
waves
have
a
wide
range
of
wavelengths
frequencies).
There
is
a
wide
range
electromagnetic
of
uses
and
dangers
associated
with
waves.
81
3.4
Light
A
LEARNING
light
the
end
should
be
of
this
able

describe

explain
the
topic
be
you
say
how
formed
situations
energy
to:
path
of
light
describe
in
a
range
A
of
light
a
lamp
energy
(taken
absorbed
boxes
operation
of
ray
box
in)
by
and
uses
produced
eclipses
radiates
is
when
the
being
light
energy
it
emitted.
in
reaches
retina
at
the
This
all
directions.
surfaces.
back
of
light
For
the
energy
example,
can
light
eye.
rays
the
by
lamp.
a
lamp
placing
We
to
a
can
produce
‘stop’
see
light.
with
these
a
Narrow
single
light
rays
slit
beams
(or
of
series
because
light
of
some
can
slits)
of
the
be
next
light
is
a
off
surfaces
into
our
eyes.
camera.
A
laser
can
look
to
but
spraying
the
path
laser
of
the
the
extended
pass
so
a
through
shadow
sprinkling
scattering
rays.
rays
talcum
and
It
is
are
allows
harmful
not
powder
us
to
to
usually
into
see
the
visible
the
the
path
straight
shadows
straight
of
line
light
from
then
region
light
light
where
completely
and
or
light
These
will
will
the
there
be
in
source.
will
be
a
If
an
opaque
region
where
object
the
light
shadow.
produce
a
very
sharp
shadow
behind
an
object.
regions
cannot
of
the
This
source
narrow
beam.
beam.
a
of
reach.
point
An
in
path
very
laser
aerosol
travels
in
opaque
boy
laser
a
causes
Light
A
the
some
beam
at
formation
cannot
Light
produce
directly
The
is
3.4.1
also
eye
of
Figure
the
shadows
including
the
is
scattered
pinhole
as
shadows
rays
to

that
absorbed
Ray
are
such
and
OUTCOMES
We
At
source
rays
blocked
all
of
dark.
will
be
source
the
The
will
produce
possible
regions
partially
ray
where
a
less
paths
some
sharp
are
of
shadow.
blocked
the
ray
will
The
be
paths
are
shaded.
is
formed.
Eclipses
Eclipses
only
demonstrate
source
of
that
visible
light
light
in
travels
the
solar
in
straight
system.
lines.
The
The
planets
Sun
and
is
the
moons
ACTIVITY
are

Construct
camera
foil
your
using
and
some
own
a
box,
visible
Solar
some
tracing
it
to
objects
view
(or
darkened
brightly
light
Produce
how
a
dates
of
guide
or
and
observed
some
of
this
sunlight.
Sun
is
very
much
larger
than
the
Moon
but
it
is
much
further
lit
sources)
in
away.
This
means
when
viewed
that
they
appear
to
be
almost
exactly
the
same
size
a
from
how
safely.
the
about
solar
they
can
Include
next
the
eclipses
for
be
the
eclipses.
directly
Sun
regions
small
in
is
which
not
only
lie
the
Earth.
between
a
point
some
within
region
total
surface
82
reflect
A
solar
eclipse
occurs
when
the
Moon
room.
lunar
happen
they
eclipse
passes

because
paper.
The
Use
only
pinhole
on
the
darkness
of
the
the
of
and
light
sunlight
penumbra
Earth’s
during
Earth
Sun
source
of
the
the
as
an
the
the
there
is
and
are
blocked
(Figure
surface
lies
This
within
dark
rotates.
3.4.2).
regions
by
experience
eclipse.
Earth
Earth
the
the
a
on
the
Moon.
partial
umbra
region
Because
Earth
These
eclipse.
and
moves
so
across
A
is
the
Earth
Moon
Sun
U
U
P
Figure
Lunar
We
3.4.2
An
eclipse
of
the
see
Umbra
Penumbra
Sun
SUMMARY
eclipse
can
=
=
the
Moon
when
sunlight
reflects
off
its
surface.
A
lunar
1
eclipse
occurs
and
the
when
the
Earth
blocks
sunlight
travelling
to
the
The
International
Moon
appears
dark
(Figure
3.4.3).
During
a
lunar
Moon
sometimes
appears
to
be
dark
red,
this
is
because
some
passes
through
the
Earth’s
atmosphere
and
reaches
the
of
and
orbits
100
at
200 km
from
a
the
Moon.
surface
of
diagram
causes
Moon’s
approximately
long
red
height
light
is
eclipse
metres
the
Space
Moon
Station
so
QUESTIONS
the
to
no
Earth.
explain
obvious
Use
why
a
it
shadow
as
orbit
it
Eclipsed
passes
between
the
Earth
Moon
and
2
the
Explain
shown
Sun.
how
in
the
Figure
equipment
3.4.5
can
be
Sun
used
to
show
travel
in
Figure
3.4.5
that
straight
light
rays
lines.
Earth
Earth’s
Figure
The
A
3.4.3
pinhole
pinhole
image
hole
An
on
in
eclipse
an
the
Moon
camera
camera
a
of
umbra
is
screen
opaque
a
simple
(Figure
sheet
optical
3.4.4).
such
as
A
instrument
pin
is
used
aluminium
used
to
foil.
to
make
The
produce
a
foil
very
is
an
small
placed
KEY
in
front
of
a
brightly
through
the
sheet
translucent
lit
pinhole.
object.
An
Rays
image
of
of
the
light
from
object
can
the
be
object
formed
on
a
1
of
POINTS
travel
Light
rays
travel
in
straight
paper.
lines
the
Screen,
film
2
or
and
ray
are
detected
reaches
Shadows
are
our
when
eyes.
formed
when
photographic
an
opaque
object
blocks
the
plate
path
Pinhole
3
Real,
Distant
of
Solar
light
rays.
eclipses
occur
when
inverted
object
image
4
Figure
3.4.4
The
pinhole
the
Moon
the
Earth
Lunar
passes
and
eclipses
between
the
Sun.
occur
when
camera
the
Earth
from
prevents
reaching
the
sunlight
Moon.
83
3.5
Reflection
When
LEARNING
light
the
end
of
should
be

and
state
strike
a
surface
they
light
may
be
absorbed,
transmitted
or
OUTCOMES
reflected.
At
rays
of
this
able
topic
Describing
the
all
follow
specifi c
laws.
you
to:
apply
Refl ections
laws
reflection
of
Reflection
occurs
when
a
ray
of
light
reaches
a
surface
or
boundary
reflection
between

describe
formed
how
in
properties
a
images
mirror
of
and
those
strikes
are
This
the
a
ray
mirror
.
For
The
reflects
off
example,
ray
the
that
a
reflection
strikes
silvered
the
surface
occurs
mirror
and
is
is
when
called
called
a
an
the
light
ray
incident
reflected
ray.
ray
images.
At
a
the
point
normal.
surface.
Ray
materials.
where
The
the
normal
When
incident
is
a
measuring
measured
relative
The
of
to
the
line
ray
touches
the
perpendicular
angles
normal,
during
not
to
mirror
(at
right
reflection
the
all
surface
we
can
angles)
angles
draw
to
a
must
be
itself.
box
Incident
For
laws
any
reflection
reflection
at
a
surface
two
laws
apply:
ray
i = r
i

the
angle
of

the
incident
reflection
ray,
is
equal
reflected
ray
to
the
and
angle
normal
of
are
incidence
all
in
the
same
plane.
Normal
r
Figure
3.5.1
shows
Experiments
show
a
simple
that
the
reflection
angle
of
in
a
plane
(flat)
incidence,
i,
mirror.
and
the
angle
of
Reflected
ray
reflection,
Mirror
The
lie
Figure
3.5.1
Investigating
the
laws
second
on
a
using
a
ray
are
law
plane
always
of
(a
equal,
reflection
flat
surface
proving
states
like
a
that
piece
the
of
first
two
law.
rays
paper).
and
This
the
normal
means
that
all
the
ray
does
not
twist
upwards
or
downwards
during
reflection.
box
Regular
Reflections
This
is
so
and
from
because
Parallel
the
rays
of
diffuse
a
mirror
the
object.
reflection
produce
reflective
light
observed
original
will
size
This
be
and
is
an
surface
reflected
shape
regular
of
the
and
the
(a
will
image
reflection
picture
mirror
is
remain
will
we
very
parallel
match
(Figure
can
see).
smooth.
that
and
of
the
3.5.2a).
b
Parallel
a
image
of
a
light
rays
from
source
Mirror
Figure
3.5.2
or
polished
surface
Reflection
paper
84
the
of
reflected
reflection
r,
is
b
from
a
Rough
mirror
diffuse.
is
a
regular
but
surface,
reflection
like
paper
from
a
sheet
of
Most
surfaces
surfaces
but
in
the
the
is
not
will
roughness
different
This
are
rays
of
in
This
parallel
according
surface
reflection
plane
When
reflected
the
directions.
diffuse
Images
smooth.
be
causes
means
(Figure
that
rays
to
these
no
of
the
light
laws
reflected
clear
image
hit
of
these
reflection
rays
will
to
be
travel
formed.
3.5.2b).
mirrors
x = y
The
image
we
see
when
we
look
into
a
mirror
is
a
virtual
image.
A
Point
object
Image
x
virtual
no
image
rays
the
of
same
Figure
cannot
light
actually
distance
3.5.3
be
the
projected
pass
behind
through
the
distances
x
onto
mirror
and
y
a
screen
the
as
are
or
image.
the
the
surface
The
object
is
because
image
in
y
O
I
is
front.
In
same.
Normals
SUMMARY
1
What
QUESTIONS
are
the
sizes
of
angles
Q,
P,
R
and
S
as
shown
in
Mirror
Figure
3.5.4?
Figure
3.5.3
The
image
formed
in
a
Mirror
plane
mirror
Normal
S
Normal
ACTIVITY
20°
R
Design
a
method
to
prove
that
P
30°
Q
the
Mirror
image
same
as
Normal
in
a
distance
mirror
the
object
is
behind
is
in
the
the
front
of
mirror
it.
Mirror
Figure
2
A
3.5.4
student
face
looks
exactly
a
Is
the
b
What
directly
30 cm
image
from
real
or
into
the
a
plane
mirror
mirror.
using
a
She
positions
her
ruler.
EXAM
In
is
the
total
TIP
virtual?
distance
from
her
face
to
the
exam
ques
tions
,
image?
mirr
ors
may
positio
ned
or
KEY
verti
cally
,
angl
e
POINTS
as
in
ques
tion
1
2
Angles
The
all
are
angle
always
of
measured
reflection
is
from
equal
to
the
the
normal.
angle
of
sure
incidence
for
to
you
the
be
1.
but
at
no rm
an
Sum
mary
If
you
measu
re
shou
ldn’ t
reflections.
no t
ho riz
onta
lly
al
mak
e
angl
es
they
give
you
any
problem
s.
3
The
image
behind
the
in
a
plane
mirror
as
mirror
the
is
virtual
object
is
in
and
front
the
of
same
the
distance
mirror.
85
3.6
Refraction
of
light
8
Light
LEARNING
travels
at
approximately
8
2.00
At
the
end
should
be
of
this
able
topic
to
you
×
describe
at
a
change
to:
how
light
boundary
10
change
point

describe
×
10
−1
m s
in
air
but
slows
to
is
m s
glass.
direction
at
is
This
the
change
boundary
always
of
speed
between
measured
causes
the
relative
two
to
the
the
ray
of
materials.
normal
light
This
at
the
refraction.
refracted
between
in
a
rectangular
block
materials
how
be
dispersed
by
a
prism
in
direction
in
of
−1
Refraction
transparent

3.00
OUTCOMES
white
into
or
a
light
When
can
the
causes
spectrum
(Figure
raindrops.
and
light
the
ray
to
3.6.1).
refracts
parallel,
the
originally
ray
refract,
When
away
ray
but
it
Refraction
enters
ends
is
to
the
from
the
a
ray
its
travelling
it
slows
path
leaves
normal.
laterally
in
block
change
light
the
up
glass
towards
the
glass
Because
in
the
down
the
same
and
the
block
two
this
normal
it
speeds
boundaries
direction
as
it
up
are
was
displaced
semi-circular
block
Lateral
If
the
incident
ray
enters
a
new
material
along
the
normal
then
displacement
Glass
the
ray
cannot
the
same
‘turn
path.
The
towards
ray
still
the
normal’
slows
down
and
or
it
continues
speeds
up.
along
This
can
be
block
demonstrated
directed
with
along
the
a
semi-circular
normal
to
the
glass
block
curved
where
surface
the
(Figure
ray
can
be
3.6.2).
r
Refraction
i
Triangular
r
<
prism
from
it
refracts
prism
are
also
the
towards
used
normal.
As
the
the
to
refract
two
normal
and
light.
refracting
as
it
As
the
leaves
surfaces
are
it
ray
enters
refracts
the
not
away
parallel
the
box
emergent
Figure
prisms
a
i
Normal
Ray
in
3.6.1
Refraction
through
rectangular
glass
ray
is
not
parallel
to
the
incident
ray.
a
block
Dispersion
All
electromagnetic
but
Incident
ray
will
travel
different
at
colours
transparent
radiation
different
of
light
materials.
travels
speeds
travel
The
size
in
at
the
other
same
speed
mediums.
at
different
of
the
speeds
change
in
In
in
in
a
vacuum
particular
glass
direction
or
other
during
P
Normal
i
at
P
refraction
depends
on
boundary
(see
and
the
change
in
the
speed
of
light
at
the
r
different
degree
Refracted
Figure
3.6.2
The
ray
refracts
boundaries
change
but
at
both
does
direction
ray
not
is
amounts.
than
called
enters
is
travelling
the
86
the
Rainbows
raindrops.
when
surface.
block
as
normal
it
to
red
For
light
dispersion
produced.
it
3.7)
are
caused
The
light
so
different
example,
as
it
has
(Figure
when
is
a
colours
violet
light
greater
of
light
refracts
change
in
will
to
a
refract
by
greater
speed.
This
effect
3.6.4).
light
dispersed
from
and
a
the
Sun
passes
coloured
through
spectral
pattern
is
ACTIVITY
Normal
Use
a
when
filter
prism
you
to
to
try
disperse
to
produce
Refraction
in
white
disperse
blue
light.
blue
light
Investigate
with
a
what
prism.
happens
(Use
a
coloured
light.)
water
Apparent
When
from
path
rays
the
of
of
light
normal.
the
ray
travel
If
will
a
ray
from
water
travels
change
into
from
such
that
air
the
the
the
rays
bottom
ray
of
refract
a
appears
pool
to
away
then
come
Real
to
actually
the
is
surface.
(Figure
SUMMARY
1
Copy
for
causes
the
pool
to
look
shallower
from
that
3.6.3
The
pool
is
deeper
than
it
it
appears
due
A
can
to
refraction.
3.6.3).
QUESTIONS
Figures
the
This
position
the
Figure
closer
position
3.6.5
incident
and
3.6.6
and
then
complete
the
ray
path
rays.
Normal
45°
Normal
45°
Figure
3.6.5
Figure
Figure
3.6.6
3.6.4
prism
disperse
2
Which
enters
3
colour
glass
Which
of
of
visible
from
these
light
slows
by
the
least
amount
when
The
higher
statements
speed
as
the
it
The
frequency
enters
longer
speed
as
the
it
is/are
correct?
glass
of
light
from
the
greater
the
change
wavelength
Alwa
ys
air.
leaves
glass
and
of
light
enters
the
smaller
the
change
in
any
will
angl
e
POINTS
When
a
of
light
travels
from
one
medium
to
another
Y
ou
it
If
the
the
ray
point
If
the
ray
no rm
al
refra
ction
.
help
you
chan
ge
muc
h
shou
ld
to
in
more
slows
of
down,
its
path
will
turn
towards
the
normal
at
sharp,
refraction.
speeds
up,
its
path
will
turn
away
from
the
of
see
that
the
direc
tion
boun
darie
s
Avoid
3
the
chan
ge
speed.
these
2
the
clear
ly.
ray
changes
draw
diag
rams
invo
lving
air.
judg
e
1
TIP
in
T
his
KEY
to
it
on

used
light.
air?
EXAM

be
white
sudd
en
usin
g
is
at
a
turn
.
the
wo rd
normal
‘bend
’.
at
4
the
White
its
point
light
of
refraction.
will
constituent
disperse
during
refraction
and
separate
into
colours.
87
3.7
Refractive
total
Snell’s
LEARNING
the
end
should

be
apply
internal
and
reflection
law
OUTCOMES
Snell’s
At
index
of
this
able
Snell’s
refractions
topic
law
states
that
the
ratio
of
the
sines
of
the
angle
of
incidence
you
and
angle
of
refraction
This
constant
at
a
boundary
is
a
constant
(Figure
3.7.1).
to:
law
to
shows
to
the
is
the
refractive
refractive
index
of
index
of
different
the
boundary.
T
able
3.7.1
materials.
calculate
sin i
change
in
angle
or
=
speeds
refractive
index,
n
sin r

find
the
critical
angle
for
a
The
same
form
of
relationship
also
applies
to
the
ratio
of
the
speed
boundary
of

describe
total
light
in
the
two
materials.
For
a
boundary
between
air
and
another
internal
transparent
material:
reflection
speed

explain
how
total
is
used
light
in
air,
v
1
=
speed
reflection
of
internal
in
of
light
in
material,
refractive
index,
n
v
optical
2
fibres.
The
two
equations
can
be
combined
sin i
to
give:
v
1
=
=
sin r
refractive
index
v
2
Normal
WORKED
EXAMPLE
1
i
Medium
1
Medium
2
A
ray
of
light
(refractive
is
refracted
index
1.50).
at
The
the
boundary
angle
of
from
incidence
air
is
into
30°.
glass
What
is
the
r
angle
of
refraction?
sin i
=
refractive
index
sin r
Figure
3.7.1
The
refractive
boundary
is
index
the
of
ratio
the
sin i
sin r
of
=
refractive
sin i
to
ratio
sin r.
of
the
This
is
speeds
also
of
sin 30°
=
=
index
0.33
1.50
the
light
–1
r
in
T
able
3.7.1
the
Examples
indices
of
for
a
refractive
ray
of
T
otal
the
vacuum
material
(or
0.33
=
19.5°
Refractive
internal
index,
index
light
and
can
1.50
water
1.33
Perspex
1.50
reaches
one
be
with
a
boundary
lower
between
reflected
by
refractive
if
critical
given
the
angle
angle
by
the
of
the
surface
incidence
(Figure
3.7.2).
is
The
instead
greater
critical
of
of
glass
high
to
being
air)
refractive
then
refracted.
the
This
than
an
angle,
angle
C,
for
a
called
the
boundary
is
1
=
refractive
index
of
boundary
2.42
During
this
material
this
88
material
(e.g.
relationship:
sin C
diamond
a
index
n
occurs
glass
reflection
from
air)
light
Material
sin
light
When
entering
a
=
materials.
process
and
process
so
the
there
is
all
of
the
process
no
loss
light
is
of
is
called
light
reflected
total
back
internal
energy.
into
the
first
reflection.
During
ACTIVITY
At
the
critical
angle
Total
internal
Incident
Incident
reflection
ray

Next
time
you
are
swimming
ray
in
P
P
i
C
Normal
at
P
Normal
at
a
pool
go
and
look
towards
Try
P
to
to
explain
the
bottom
the
the
surface.
effects
that
r

you
see.
you
are
Flash
a
Refracted
ray
Reflected
a
long
light
fibre
3.7.2
Total
internal
than
the
critical
reflection
WORKED
The
is
(r
EXAMPLE
refractive
the
critical
index
angle
reflection
=
angle
occurs
C.
The
if
the
angle
reflected
ray
of
only
do
this
if
supervised.
into
one
optic
end
cable.
of
You
ray
should
Figure
Note:
being
incidence
follows
the
is
the
greater
laws
of
see
other
cable
is
the
end
flashing
even
coiled
at
when
the
up.
i).
2
of
for
an
air
this
to
Perspex
boundary
is
1.50.
What
boundary?
Ray
1
sin C
1
=
=
=
0.66
Normal
refractive
index
of
boundary
1.50
–1
C
=
sin
0.66
=
41.8°
Optical
fibre
Optical
signals
fibres
enters
the
of
glass.
the
glass
use
(Figure
fibres
even
The
when
SUMMARY
the
process
3.7.3).
and
ray
A
ray
travels
can
the
of
of
along
travel
fibre
is
total
light
it
for
internal
(more
by
being
several
coiled
in
refl ection
usually
to
transmit
infra-red
refl ected
kilometres
at
radiation)
the
through
surface
the
loops.
QUESTIONS
Figure
1
Copy
rays
T
able
3.7.2
entering
a
and
then
material
complete
from
it
using
Snell’s
law
Rays
in
an
optical
fibre
air.
KEY
T
able
3.7.3
for
POINTS
3.7.2
1
Angle
of
Angle
Refractive
of
index
Speed
of
light
The
ratio
of
the
sines
of
in
angles
of
incidence
and
−1
incidence/
refraction/
degrees
degrees
of
boundary
30
material/m s
refraction
is
called
refractive
the
a
constant
index.
1.33
2
20
The
the
50
refractive
index
is
also
1.45
30
ratio
light
in
of
the
the
speed
two
of
materials.
8
45
1.5
×
10
3
When
a
along
2
Draw
a
bottom
the
diagram
of
water.
a
showing
pond
so
Calculate
that
the
a
it
ray
of
just
critical
light
travelling
escapes
angle
for
from
this
from
the
the
surface
boundary.
totally
of
many
is
lost
ray
an
of
light
optical
internally
times
at
but
these
passes
fibre
it
reflects
little
energy
reflections.
89
3.8
Converging
T
ypes
LEARNING
the
end
of
this
topic
be
able
are
(Figure
describe
the
path
through
a
(convex)
lens
describe
the
of
rays
that
the
converging
a
images
of
Lenses
glass
or
usually
plastic
have
which
two
cause
curved
refraction
surfaces
and
of
each
converging
are
refraction.
refraction
of
the
many
In
order
takes
to
place
simplify
for
each
diagrams,
ray
and
this
we
assume
happens
in
lens.
shapes
of
lens
but
there
are
only
two
main
effects:
formed

by
causes
single
centre
There

blocks
3.8.1).
to:
surface

curved
you
light
should
lens
OUTCOMES
Lenses
At
of
lenses
A
converging
lens
brings
rays
of
light,
parallel
to
the
principal
axis,
lenses.
together.

A
diverging
apart.
The
Converging
See
lens
spreads
rays
of
light,
parallel
to
the
principal
axis,
3.9.
principal
axis
is
an
imaginary
line
which
passes
through
the
lenses
centre
The
it
of
Plano-convex
lens
principal
and
the
lenses
Bi-convex
the
focus
centre
cause
and
lies
of
more
is
perpendicular
on
the
the
lens
is
refraction
to
principal
the
than
it.
axis
focal
weak
and
the
length,
lenses
f,
and
distance
of
so
the
between
lens.
have
Strong
shorter
Converging
focal
lengths.
meniscus
Diverging
Converging
lenses
Figure
These
the
3.8.2
rays
lens
Bi-concave
Plano-concave
shows
are
so
(marked
a
set
parallel
that
F).
lenses
they
Each
all
lens
of
to
rays
the
meet
has
passing
principal
at
two
a
through
axis
point
and
called
principal
a
converging
they
the
are
lens.
refracted
principal
by
focus
foci
Diverging
meniscus
Figure
3.8.1
A
range
of
lens
shapes
Parallel
f
rays
F
L
Figure
The
90
F
=
principal
f
=
focal
L
=
optical
3.8.2
focal
passes
through
would
be
(real)
centre
Parallel
plane
focus
length
is
a
the
brought
rays
passing
plane
a
a
converging
perpendicular
principal
to
through
focus
focus.
on
a
to
Parallel
screen
the
rays
lens
principal
from
placed
in
a
the
axis
distant
focal
that
object
plane.
Images
We
can
from
the

from
find
an
the
object.
Ray
1
travels
Ray
2
so
Figure
Ray
3
it
the
it
of
the
3.8.3
lens
image
three
place
through
reaches
principal
parallel
passes
through
takes
passes
When
the
to
that
passes
refraction

properties
In
lenses
by
rays
analysing
are
drawn
the
ray
from
paths
the
top
of
object.
refracted

converging
the
the
to
the
principal
axis.
through
the
principal
focus.
optical
there
the
lens
is
no
centre
change
principal
it
is
focus
refracted
of
of
lens
ray
and
as
is
no
direction.
on
so
the
The
the
that
it
left
of
the
becomes
lens.
parallel
to
axis.
Converging
lens
EXAM
TIP
1
2
Draw
ing
Object
requi
res
Principal
F
3
Principal
2F
axis
axis
Real
Measu
re
ray
the
caref
ully
use
a
and
sharp
care.
distan
ces
image
(diminished)
diag
rams
great
alwa
ys
penc
il
and
ruler
.
Figure
The
3.8.3
three
should
rays
of
rays
be
original
An
meet
able
object
light
image
to
formed
and
see
by
form
that,
in
pass
converging
an
image
this
case,
(diminished),
really
a
it
through
is
on
the
upside
the
lens
the
down
image
right
image
and
is
of
the
(inverted)
so
it
lens.
smaller
is
a
You
than
and
real
the
that
image.
ACTIVITY
Place
rays
a
of
converging
light
principal
Draw
and
focus
two
lens
and
more
versions
between
F
and
2F
b
between
F
and
the
each
case,
front
what
measure
a
For
in
describe
draw
of
of
a
ray
happens
the
focal
Figure
box
to
producing
the
length
3.8.3
but
rays.
of
the
place
parallel
Find
the
lens.
the
object:
lens.
the
three
rays
and
describe
the
KEY
image.
1
POINTS
A
converging
rays,
axis,
SUMMARY
parallel
so
that
Define
and
the
key
principal
terms:
focal
length,
focal
plane,
principal
focal
Draw
axis
of
a
scale
each
focal
they
principal
are
focus
together
at
the
point.
axis.
2
2
refracts
the
QUESTIONS
brought
1
lens
to
diagram
0.5 cm
length
apart
5 cm.
showing
as
they
five
pass
rays
parallel
through
a
to
the
principal
converging
lens
A
diverging
rays,
axis,
lens
parallel
so
come
that
from
to
refracts
the
they
the
principal
appear
focal
to
point.
91
3.9
Diverging
the
Figure
LEARNING
the
should
end
be
eye
3.9.1
of
this
able
topic
rays
come
you
shows
describe
the
through
a
spread
from
principal
to:
focus

a
path
of
diverging
is
one
focus
the
out
set
of
rays
(diverge)
passing
point.
and
focal
As
the
for
in
a
such
a
distance
between
that
the
diverging
lens,
diverging
the
this
lens
appear
lens.
point
and
is
the
to
all
called
the
principal
length.
rays
(concave)
images
Parallel
formed
rays
lenses.
F
Figure
To
find
F
=
principal
f
=
focal
3.9.1
Images
Figure
a
they
f
describe
by
through
way
converging
lens

and
OUTCOMES
The
At
lenses
Rays
in
the
focus
L
(virtual)
length
passing
through
diverging
properties
of
a
diverging
lens
lenses
an
image
produced
by
a
diverging
lens
draw
3.9.2
three

Ray
rays
1
is
appears
as
for
a
parallel
to
converging
to
come
the
from
lens
principal
the
(Figure
axis
principal
and
3.9.3):
is
focus
refracted
(the
so
dotted
that
line
it
shows
this).

Ray
in

2
passes
straight
through
the
optical
centre
without
a
change
direction.
Ray
3
is
the
ray
beyond
the
lens.
when
passes
it
which
This
would
ray
through
is
pass
through
brought
the
the
parallel
to
principal
the
focus
principal
axis
lens.
f
f
1
3
Object
ACTIVITY
2
Principal
Place
a
diverging
lens
in
F
F
axis
axis
Virtual
of
a
ray
box
producing
parallel
image
rays
of
light
and
happens
to
principal
focus
focal
length
the
of
describe
rays.
and
the
Find
what
the
measure
the
lens.
Figure
92
Principal
front
3.9.3
An
image
formed
by
a
diverging
lens
As
before,
formed
the
image
means
you
Human
a
is
that
could
Our
the
eyes
the
not
also
rays
acts
a
and
and
not
to
come
the
upright.
actually
screen
there
from
principal
The
pass
and
a
point.
axis.
image
You
is
through
see
the
The
image
should
also
that
see
virtual.
point
is
that
This
and
so
image.
vision
contain
at
appear
point
do
place
two
lens
muscles
objects
rays
this
diminished
converging
ciliary
three
between
with
are
a
lens
a
used
different
as
surfaces
variable
to
a
the
The
fixed
act
focal
stretch
distances.
with
which
lenses.
length
lens
outer
focal
as
to
The
(Figure
allow
layer
of
lens
3.9.4).
us
the
eye’s
to
Small
focus
eye,
is
the
on
cornea,
Cornea
length.
Retina
Correcting
Both
converging
vision

A
vision
(T
able
Lens
and
diverging
lenses
are
used
to
correct
defects
of
3.9.1).
short-sighted
(near-sighted)
person
suffers
from
myopia.
The
Ciliar y
lens
in
their
objects.
a
focus
This
The
in
poor
diverging
of

A
light
the
lens
focus
eye.
retina
used
to
power
can
T
able
to
used
reach
of
blurred
this
a
the
vision
correct
from
image
problem
to
object
instead
of
of
focus
would
clearly
distant
myopia
by
on
be
on
muscles
distant
brought
its
to
surface.
objects.
diverging
Figure
3.9.4
The
human
eye
A
the
rays
cornea.
person
as
enough
distant
retina
to
(such
light
thin
blurred
(far-sighted)
a
the
3.9.1
be
from
eye’s
leads
objects
Rays
so
become
light
the
they
correct
of
of
of
focusing
long-sighted
the
cannot
rays
front
before
cannot
to
eye
the
the
is
by
suffers
words
object
formed.
from
on
a
would
A
increasing
hyperopia.
page)
be
that
focused
converging
the
overall
They
are
lens
close
behind
can
be
converging
eye.
Defects
not
of
vision
and
their
correction
(refraction
by
the
cornea
is
shown)
Myopia
Hyperopia
Before
After
correction
SUMMARY
1
Draw
axis
a
scale
each
focal
QUESTIONS
diagram
0.5 cm
length
apart
showing
as
they
five
pass
rays
parallel
through
a
to
the
principal
diverging
lens
of
KEY
10 cm.
1
2
‘The
and
image
smaller
Construct
POINT
formed
than
some
by
the
ray
a
diverging
object.’
diagrams
Is
lens
this
to
is
always
statement
test
your
virtual,
true
answer.
or
upright
false?
A
diverging
parallel
so
that
from
to
they
the
lens
the
refracts
principal
appear
focal
to
rays
axis
come
point.
93
3.10
Magnification
As
LEARNING
you
size
At
the
end
should
be
have
seen,
the
of
this
able
topic
as
the
object)
you
or
object.
The
diminished
calculate
the
produced
or
by
a
other
determine
of
a
an
object
(smaller
be
are
not
than
magnified
always
the
(larger
the
than
same
the
object).
and
image
height
magnifying
of
the
images
is
defi ned
by
an
equation
comparing
the
lens
image

of
may
magnification
Magnification
glass
image
to:
Magnification

images
OUTCOMES
the
focal
converging
height
to
the
object
height:
length
linear
lens
magnification,
m,
height
of
image
height
of
object
=
experimentally.
Magnification
and
object
distance
Converging
The
linear
magnification
of
a
converging
lens
can
also
be
found
lens
X
using
the
I
L
object
formation
LOX
O
the
are
(image
distance
of
similar
height)
an
image
triangles
is
and
the
by
and
same
a
distance.
converging
so
as
v
u
image
the
the
ratios
ratio
of
Figure
lens.
of
u
OX
to
image
distance,
v
object
distance,
u
3.10.1
The
shows
triangles
(object
LIY
height)
and
to
IY
v
Y
Linear
magnification,
m,
=
v
A
m
×
A
Figure
3.10.1
Linear
magnifying
magnifying
glass
uses
a
single
converging
to
work
focal
EXAMPLE
image
of
effectively
length.
This
an
the
object
object
(Figure
needs
arrangement
will
3.10.2).
to
be
a
lens
forms
candle
10.0 cm.
of
the
an
with
If
lens
a
the
is
size
image
of
height
of
magnification
1.60
of
the
produce
produce
a
the
a
to
magnifying
the
lens
magnified,
than
virtual
what
is
virtual
i
magnifying
ii
erect
ii
instrument
eyepieces
iii
magnified
spectacles,
as
iv
on
of
the
the
lens
iii
same
as
O
side
for
glass
correction
long-sightedness
and
away
candle?
F
magnification
O
L
=
Eye
height
of
image
height
of
object
Figure
Height
of
object
height
linear
of
3.10.2
A
magnifying
glass
=
image
magnification
The
The
lens
formula
relationship
distance,
v
and
between
the
object
the
focal
=
6.25 cm
1
1
1
1.60
=
f
94
length
distance,
10.0 cm
=
image.
Uses:
i
F
Linear
glass
the
1
further
actual
to
For
closer
Image:
A
lens
magnification
magnified
WORKED
glass
u
+
u
v
u
is
of
a
given
lens,
by:
the
image
When
using
the
lens
formula
the
distances
are
positive
for
real
images
WORKED
but
are
negative
produce
a
for
virtual
virtual
image
images.
0.1 m
For
from
example,
the
lens
a
and
diverging
so
v
would
lens
be
−0.1 m.
A
lens
has
The
lens
formula
can
be
used
to
determine
the
focal
length
of
a
illuminating
an
object
and
positioning
the
lens
to
form
a
a
on
a
screen
(Figure
3.10.3).
The
distance
between
used
focal
produce
the
lens
object
is
measured
as
is
the
distance
between
the
lens
the
and
These
two
distances
can
be
substituted
into
the
formula
the
focal
length
of
the
of
camera
0.10 m.
a
clear
image
on
a
image
behind
must
the
be
lens.
formed
How
the
lens
should
the
far
object
to
be
find
simple
the
from
screen.
a
and
0.20 m
the
in
length
clear
CCD
image
2
lens
To
by
EXAMPLE
may
positioned
to
produce
this
lens.
clear
image?
1
1
1
=
v
u
+
f
u
v
White
Light
box
1
screen
1
1
=
+
0.10 m
u
0.20 m
1
1
1
=
Pearl
–
lamp
Converging
u
0.10 m
0.20 m
lens
Real
Front
of
object
light
or
box:
illuminated
on
1
image
=
screen
10
–
5
=
5
u
cross-wires
1
Figure
3.10.3
Finding
the
focal
length
using
the
lens
formula
u
=
=
0.20 m
5
SUMMARY
1
In
which
QUESTIONS
of
these
three
situations
is
the
magnification
the
largest?
ACTIVITY

An
object
of
height

An
object
of
13 cm

An
object
of
3 cm
5.0 cm
producing
producing
producing
an
an
an
image
image
image
of
of
of
20 cm.
1.0 cm.

7 cm.
Perform
an
find
focal
the
range
2
Copy
T
able
3.10.1.
Then
use
the
lens
formula
and
to
complete
the
table
for
a
range
of
converging
lenses.
results
the
lens.
3.10.1
curvature
Image
Focal
distance
distance
length
Magnification
focal

2.00 m
Use
see
0.25 m
the
a
is
of
the
lens
the
and
the
glass
happens
to
when
positioned
the
beyond
focal
length
the
of
image
the
lens.
produced.
POINTS
The
magnification
image
to
the
of
height
an
of
image
the
is
the
original
ratio
of
the
height
of
T
ake
object.
The
the
The
magnification
object
focal
distance
is
also
the
ratio
of
the
image
distance
length
of
image
care
a
lens
can
distance
be
found
using
the
from
lens
the
when
fo rm
ula,
dealin
g
distance.
and
to
TIP
an
lens
3
the
0.2
EXAM
2
curvature
between
magnifying
what
Describe
1
the
6 cm
14 cm
KEY
to
length.
object
15 cm
to
a
Compare
Describe
relationship
Object
of
lenses.
of
T
able
length
magnification
your
equation
of
investigation
with
usin
g
as
you
the
are
recipr
ocals.
object
formula.
95
3.11
Diffraction,
and
theories
nature
Scientists
LEARNING
the
end
should

be
outline
have
of
this
able
the
topic
A
particle
of
describe
Young’s
and
and
very
brief
is
behaviour
behaving
as
a
of
light
stream
for
of
centuries
particles
and
or
as
have
waves.
history…
Huygens
the
of
formulated
concept
to
a
theory
describe
that
reflection
light
and
travelled
as
refraction
in
a
wave
terms
of
evidence
Newton
believed
that
light
consisted
of
a
stream
of
particles
he
wave
corpuscles.
He
used
this
model
to
describe
the
behaviour
of
light
light
the
this
wavefronts.
slit
the
used
called
behaviour
it
wave
Isaac
demonstrating
describe
light
light
experiment

the
the
you
to:
and

studied
whether
Christiaan
theories
of
about
OUTCOMES
debated
At
interference
interference
and
his
ideas
were
generally
accepted.
of
Thomas
Young
devised
experiments
which
demonstrated
the
wave
waves.
behaviour
explained
theory
of
if
was
light
Albert
are
Einstein
experimental
Produce
a
detailed
the
history
understanding
of
were
results
a
stream
and
described
used
result
a
of
of
in
more
the
experiments
particles
replaced
particle
called
these
with
detail
model
of
and
the
so
could
the
wave
not
be
particle
theory.
These
below.
light
‘photoelectric
to
explain
effect’.
the
This
could
not
of
using
wave
theory.
our
Today
light.
it
is
particle
accepted
behaviours
Diffraction
When
a
spreads
The
water
out.
amount
(Figure
a
of
wave
This
of
gap
that
in
light
has
different
both
wavelike
properties
and
situations.
waves
passes
process
is
diffraction
3.11.1).
through
that
Maximum
roughly
through
a
takes
same
size
we
and
place
diffraction
the
gap
diffraction
see
the
place
that
for
depends
takes
as
can
occurs
on
when
all
the
wave
types
the
size
the
wavelength
a
of
of
of
wave
the
waves.
the
b
beam
ACTIVITY
Use
the
a
ripple
tank
interference
formed
by
through
to
Diffracted
patterns
waves
two
observe
wavefronts
passing
narrow
gaps.
Figure

Use
a
laser
to
interference
when
light
observe
patterns
passes
3.11.1
Diffraction
of
water
waves
a
at
a
wide
gap
b
at
a
narrow
gap
the
formed
through
Light
diffracts
when
it
passes
through
a
gap.
As
the
wavelength
−6
two
very
narrow
slits.
of
light
is
very
noticeable
evidence
96
small
when
that
(around
the
light
is
gaps
0.5
are
×
very
behaving
like
10
m),
narrow.
a
wave.
this
This
process
is
diffraction
gap
passes
wave.
Vibrating

be
timeline
explained
about
The
abandoned
experiments
ACTIVITY
light.
only
gives
Interference
When
two
and
waves
superimpose
meet
(Figure
waves
are
At
points
where
waves
cancel
each
trough).
This
At
points
other
increase.
is
This
and
two-slit
pass
3.11.2).
separate
some
the
simply
other
a
crest
two
out
will
each
other,
displacements
the
waves
caused
by
the
together.
waves
destructive
is
through
The
added
the
experiment
overlap
(for
the
example,
superposition
when
a
crest
of
the
meets
a
interference
meet
constructive
a
crest
and
the
displacements
will
interference
Figure
3.11.3
T
wo
an
a
Destructive
tnemecalpsiD
+
position
=
interference
tnemecalpsiD
tnemecalpsiD
0
Figure
3.11.4
tnemecalpsiD
+
=
An
1
0
Sketch
what
of
a
diagram
as
waves
2
Why
do
they
pattern
(Figure
formed
by
the
waves
is
an
interference
3
3.11.3).
we
in
indicates
Thomas
Young
investigated
what
happened
when
light
clear
two
very
interference
through
two
produce
this
narrow
gaps.
patterns
gaps
(Figure
effect.
The
in
He
the
3.11.4).
patterns
found
same
A
that
way
as
stream
could
only
the
light
water
of
be
as
a
particles
would
explained
if
not
light
Digital
collecting
KEY
nature
however,
cameras
light
packets
as
POINTS
There
have
been
of
several
energy
in
of
light
be
explained
photovoltaic
small
energy
the
behaviour
of
particle
or
light.
light
cannot
and
about
packets,
cells
by
the
behave
similar
to
wave
as
if
model
they
particles.
Diffraction
are
called
and
interference
of
experiments
provide
evidence
the
are
for
wave
These
behaviour
small
behaves
was
2
light.
light
that
wave.
particle
effects,
evidence
topic
that
see
waves?
passing
wave
Some
the
this
normally
light
wave.
theories
The
a
produces
waves
1
travelling
through
passed
a
through
showing
water
pass
not
of
Summarise
found
to
entrance.
diffraction
resulting
pattern
QUESTIONS
happens
waves
Superposition
interference
0
harbour
pattern
as
superimpose.
0
SUMMARY
The
waves
0
Constructive
3.11.2
produce
pattern
tnemecalpsiD
tnemecalpsiD
0
Rest
Figure
waves
interference
the
b
water
interference
of
light.
photons
97
3.12
Sound
Sound
LEARNING
At
the
end
should

produced
of
this
how
compare
topic
objects.
Typical
sources
include:

the
vibrating

the
skin

moving

vibrating

a
strings
on
a
guitar
you
on
a
drum
to:
sound
columns
of
air
in
a
woodwind
instrument
waves
vocal
chords
sounds
and
in
terms
when
you
speak
drill
being
used
and
to
to
pitch.
Sound
waves
passed
to
Wires
of
a
sound
power
bell
propagate
medium
from
an
remove
the
to
A
on
placing
road.
waves
air
(travel)
bell
to
quieter
longitudinal
because
particle.
inside
(Figure
becomes
as
necessary
particle
electric
the
is
a
3.12.1).
until
This
glass
it
the
can
waves
be
jar
and
the
air
is
cannot
be
must
using
a
removed,
heard
at
all.
a
be
demonstrated
bell
As
through
vibrations
by
vacuum
the
pump
sound
This
is
of
because
supply
there
is
Sound
removed
a
up
loudness
medium.
using
dig
amplitude
amplitude
frequency
to
of
Propagation
relate
Air
vibrating
produced
frequency

by
OUTCOMES
able
describe
are

be
is
waves
no
longer
waves
are
rarefactions
a
medium
for
composed
which
spread
of
the
a
out
sound
series
from
of
the
waves
to
pass
through.
compressions
source
(Figure
and
3.12.2).
vacuum
The
compressions
are
regions
of
air
(or
another
medium)
where
the
pump
particles
have
rarefactions
Bell
jar
Bell
works
been
are
compressed
regions
where
more
the
closely
particles
together
are
while
further
the
apart.
but
Compressions
cannot
be
heard
Loudspeaker
Figure
3.12.1
When
from
the
the
longer
air
jar
be
is
removed
the
bell
can
Rarefactions
no
heard.
Figure
3.12.2
The
Describing
T
able
3.12.1
Sound
travels
at
Medium
in
different
Approximate
and
and
rarefactions
displaying
in
a
sound
wave
sounds
different
Just
speeds
compressions
like
all
other
waves,
sound
waves
have
amplitude
and
frequency.
media

The
greater

The
higher
the
amplitude
of
a
sound
the
louder
it
is.
speed
the
frequency
of
the
sound
the
higher
the
pitch.
−1
of
air
sound/m s
340
water
1500
steel
6100
Representing
Sound
energy
on
the
sound
98
waves
connected
to
into
sound
can
a
an
be
as
electrical
a
on
represented
microphone.
oscilloscope.
wave
waves
The
trace
The
signal
an
on
the
the
screen
microphone
and
this
oscilloscope
on
oscilloscope
screen.
signal
then
of
an
oscilloscope
converts
controls
displays
the
the
the
sound
display
‘shape’
of
the
On

the
The
oscilloscope
height
wave.

The
of
the
period
waveform
wave.
of
is
show
between
sound
period
this
waves
distance
the
This
of
T
aller
display:
the
the
The
related
to
the
amplitude
of
the
sounds.
peaks
closer
sound
inversely
is
louder
on
the
the
wave
peaks
are
represents
together
the
the
a
Loud
and
high-pitched
b
Loud
and
low-pitched
c
Quiet
period
shorter
wave.
proportional
to
together
peaks,
the
frequency
(
frequency
=
1
period
of
)
and
the
sound
Most
They
so
the
sound.
closer
Figure
3.12.3
the
shows
the
higher
oscilloscope
the
traces
of
frequency
simple
waves.
sounds
are
are
much
composed
of
more
waves
complex
of
than
different
these
single
frequencies
and
Figure
on
in
each
other.
Figure
produces
more
complicated
(higher
pitch
than
a)
waveforms
as
3.12.3
Sound
shown
on
an
waves
represented
oscilloscope
screen
3.12.4.
SUMMARY
1
This
high-pitched
frequencies.
superimposed
Why
do
QUESTIONS
you
hear
distorted
sounds
when
you
are
swimming
underwater?
Figure
2
Sketch
a
diagram
represented
a
A
high
b
A
sound
of
3
on
Use
an
with
in
wave
how
oscilloscope
frequency
sound
the
showing
sound
half
part
speed
the
these
two
sounds
would
of
wavelength
in
with
low
frequency
and
twice
the
water
c
in
steel.
(The
speed
T
able
sound
equation
for
a
flute
to
find
the
frequency
of
a
sound
an
oscilloscope
to
compare
1.0 cm:
waveforms
in
the
different
media
is
shown
produced
musical
by
instruments
or
forks.
in
3.12.1.)
WORKED
KEY
trace
a
ACTIVITY
tuning
of
on
amplitude
a
different
in
played
amplitude.
air
b
oscilloscope
screen:
the
a
An
note
Use
wave
3.12.4
be
POINTS
The
EXAMPLE
period
of
a
sound
wave
is
–3
4.0
1
Sound
waves
are
produced
by
vibrating
objects
×
10
s.
including
What
is
the
frequency
of
the
loudspeakers.
wave?
2
Sound
waves
travel
as
longitudinal
waves
through
a
medium
1
composed
of
a
series
of
compressions
and
f
rarefactions.
=
T
1
3
The
higher
the
frequency
of
a
sound
the
higher
the
pitch
of
=
–3
the
4
The
4.0
sound.
greater
the
amplitude
of
a
sound
the
louder
the
sound.
=
×
10
s
250 Hz
99
3.13
Experimenting
sound
The
LEARNING
At
the
end
should
be
of
this
able
describe
be
waves
behaviour
of
sound
waves
OUTCOMES
topic
Reflection
you
to:
Sound

with
how
reflected,
sound
rigid
can
refracted
can
surfaces
waves
and
waves
are
be
cause
called
reflected
the
just
strongest
echoes
(Figure
like
any
other
reflections.
wave.
The
Smooth
refl ected
and
sound
3.13.1).
diffracted
Refraction

describe
sound

interference
waves
describe
used
of
in
Sound
how
sound
pre-natal
materials
can
scans
to
be
also
and
will
waves
as
the
Warmer
Cooler
lower
of
air
air
air
–
they
the
can
temperatures
when
change
because
increases
sound
testing.
waves
another
bend
higher
as
they
3.13.2).
the
speed
of
of
is
they
The
the
travel
This
ground
when
speed.
temperature
(Figure
near
direction
change
air
cooler
is
from
of
layers
most
than
the
one
sound
increases.
through
effect
move
speed
This
of
air
above
air
means
at
noticeable
air
material
in
that
different
at
night
it.
sound
–
speed
sound
Source
of
sound
Observer
Ground
Figure
3.13.2
Sound
waves
cooler
can
than
follow
a
air
on
curved
a
summer
path
evening
through
a
temperature
gradient.
Sound
Diffraction
waves
Sound
Figure
3.13.1
An
echo
rigid
from
a
smooth
waves
so
they
are
as
they
pass
have
a
much
diffracted
easily
greater
by
wavelength
larger
gaps.
than
Sound
light
waves
waves
will
and
spread
and
through
doorways
or
around
corners
as
their
wavelength
surface
is
similar
to
the
size
of
these
gaps.
Interference
When
two
sound
waves
meet
top
each
they
interfere.
The
waves
are
ACTIVITY
superimposed

Investigate
waves
of
follow
reflection
cardboard
sound

whether
Find
the
identical
laws
using
tubes
sound
to
direct
pattern
the
waves.
out
about
frequency
dolphins.
waves
also
the
range
of
Produce
bats
how
they
regions
be
of
used
then
connected
front
will
of
to
them.
This
louder
the
than
this
the
interfere
where
other.
If
effect
same
two
no
sources
can
source
pattern
and
two
will
detected.
will
have
sound
waves
be
will
producing
form
an
regions
be
constructively
interference
where
heard.
an
T
wo
the
There
interfere
will
and
the
normal.
and
report
Using
about
in
are
destructively
be
sound
hearing
a
signal
loudspeakers
some
on
sense
prey
sound
waves
and
If
the
speed
of
sound
is
known
then
we
can
measure
distances
by
predators.
recording
100
the
time
taken
for
sound
to
reach
us.
For
example,
during
a
storm,
light
sound
takes
how
far
from
a
away
WORKED
A
the
lightning
lighting
EXAMPLE
lightning
later.
a
measureable
How
strike
far
reaches
of
us
time
almost
allowing
instantly
us
to
but
the
calculate
struck.
1
hits
away
strike
amount
a
tree
did
and
the
the
thunder
lightning
distance
is
heard
4
seconds
strike?
(m)
–1
Speed
(m s
)
=
time
(s)
–1
distance
=
speed
×
time
=
340 m s
×
4 s
=
1360 m
Figure
3.13.3
A
lightning
strike
Ultrasound
High
and
frequency
so
are
produce
Because
easily
or
In
ultrasound
audible
produce
care,
(Figure
echoes
(above
20 kHz)
ultrasound.
pulses
to
pulses
sound,
detect
can
be
they
are
not
Animals
as
bats
by
or
humans
dolphins
obstacles.
directed
can
detectable
such
be
in
used
narrow
to
beams
make
more
measurements
images.
pre-natal
the
as
ultrasound
than
foetus
sounds
classed
ultrasound
3.13.4).
of
these
The
pulses
pulses
pulses
are
are
used
reflect
off
processed
by
to
form
the
a
an
image
different
computer
of
tissues
to
form
the
and
an
Figure
3.13.4
An
a
image.
much
An
Unlike
safer
X-rays,
to
as
shoals
pulse
pipework,
of
fish
does
not
cause
ionisation
and
so
image
of
is
use.
ultrasound
such
ultrasound
ultrasound
foetus
near
can
to
a
also
be
measure
boat
used
the
(Figure
to
‘see’
depth
of
into
the
solid
materials
sea-bed
or
to
detect
3.13.5).
Transmitter
WORKED
EXAMPLE
2
Sea-bed
An
ultrasound
pulse
is
used
to
detect
a
crack
in
a
metal
pipe.
The
−1
pulse
travels
at
6000 m s
in
the
metal
and
the
echo
is
received
Figure
4.0 μs
after
the
pulse
is
sent.
How
deep
within
the
pipe
–1
Distance
The
=
pulse
0.012 m
speed
has
×
time
travelled
within
the
to
=
6000 m s
the
crack
is
the
Using
and
4.0
back
×
10
and
s
so
=
the
crack
is
pipe.
POINTS
Sound
waves
They
along
a
road
you
hear
an
ambulance
siren
can
corner
but
you
cannot
see
the
ambulance.
Draw
explain
how
this
can
A
dolphin
produces
a
sound
pulse
which
reflects
off
a
fish
be
hunting.
The
echo
of
the
pulse
second
is
detected
by
the
is
after
the
1500 m s
.
pulse
was
each
and
other.
detect
sent.
The
speed
of
can
be
objects
used
by
echo
dolphin
sound
and
to
measure
in
distances.
−1
water
diffracted
with
Ultrasound
location
0.4
reflected,
it
to
is
same
waves.
happen.
2
2
the
other
a
interfere
and
as
from
refracted,
the
diagram
share
QUESTIONS
walking
around
to
0.024 m
behaviours
While
pulses
depth
–6
×
1
1
sound
measure
KEY
SUMMARY
3.13.5
crack?
How
far
apart
are
the
dolphin
and
the
fish?
101
Section
SECTION
1
The
3:
Practice
relationship
and
the
3
angles
Practice
exam
between
of
exam
questions
questions
the
incidence
refractive
and
index
refraction
B
for
Displacement/cm
a
ray
glass
crossing
is
given
the
boundary
between
air
and
by:
3
sin i
refractive
index
=
2
sin r
1
During
an
experiment
to
measure
the
0
refractive
index
of
a
glass
block
the
following
–1
results
were
obtained.
–2
Angle
of
10
15
20
25
30
35
–3
incidence,
Time/s
i/degrees
3
Angle
of
7.0
10.8
14.3
17.6
21.2
On
a
calm
day
you
can
see
your
reflection
24.2
when
looking
into
a
pond.
When
the
pond’s
refraction,
surface
is
disturbed
you
can
no
longer
see
a
r/degrees
reflection.
Why
is
this?
sin i
4
The
electromagnetic
(EM)
spectrum
consists
of
sin r
a
series
a
a
Copy
and
complete
the
table
of
State
waves.
two
properties
electromagnetic
calculating
the
values
for
sin i
and
Plot
a
suitable
and
sin r
graph
using
the
values
for
allows
you
to
all
have
in
common.
Copy
obtain
a
and
complete
this
table
showing
sin i
the
which
waves
sin r
b
b
which
by
EM
spectrum
in
order
of
increasing
value
wavelength.
for
2
the
Diagram
graph
a
refractive
A
for
shows
a
water
a
index
for
the
glass
block.
wave
displacement–time
and
graph
diagram
for
a
B
same
Visible
Radio
rays
light
waves
shows
particle
in
c
the
Gamma
distance–displacement
Which
of
the
regions
electromagnetic
a
of
the
wave.
spectrum:
State:
i
the
wavelength
ii
the
amplitude
iii
the
period
of
of
of
the
the
the
i
has
the
lowest
ii
is
a
major
iii
is
used
frequency?
wave
cause
of
skin
cancers?
wave
in
radiotherapy
to
treat
wave.
cancers?
b
Calculate
the
speed
of
the
wave.
5
A
An
oscilloscope
received
Displacement/cm
different
nearby.
from
a
is
tuning
These
used
to
display
microphone
forks,
signals
A
and
are
signals
when
B,
are
shown
in
two
struck
the
3
diagrams
opposite.
The
oscilloscope
has
been
2
adjusted
so
that
each
horizontal
division
1
represents
0
a
time
period
of
2 ms.
–1
a
Which
of
louder
sound?
the
tuning
Which
of
higher
pitch?
forks
produced
the
forks
produced
the
–2
–3
Distance/cm
b
102
the
tuning
c
Find
the
frequency
of
tuning
fork
A.
7
During
pulse
d
Without
further
calculation,
state
of
tuning
fork
medical
used
to
examination
measure
the
an
ultrasound
thickness
of
a
the
fat
frequency
a
is
layer
in
a
patient’s
skin.
Sound
travels
at
B.
−1
630 m s
pulse
Sine
wave
is
in
a
How
b
Why
c
thick
are
Why
The
0.3 μs
echo
after
8
A
a
fat
lower
the
from
pulse
the
is
sent.
box
State
the
b
Copy
and
and
two
a
scans
the
used
law
curved
laws
of
complete
reflected
frequencies
used
instead
of
care?
investigated
ray
layer?
frequencies?
pre-natal
a
the
the
ultrasound
in
student
using
is
ultrasound
of
are
X-rays
wave
tissue.
A
instead
Sine
this
received
of
reflection
mirror
as
shown.
reflection.
the
diagram
showing
ray.
B
c
Mark
its
on
the
angle
of
reflection
and
state
value.
Normal
70°
Mirror
6
During
an
experiment
to
measure
the
speed
of
9
sound
in
metal,
two
microphones
are
A
group
of
properties
to
a
long,
thin
steel
bar
.
The
first
the
stopclock
when
it
detects
the
bar
.
The
second
investigating
constructed
a
optical
triangular
microphone
diamond.
Diamond
has
a
prism
refractive
index
sound
of
in
have
microphone
from
starts
scientists
attached
is
2.40.
50 cm
8
further
when
the
a
along
it
the
detects
stopclock
What
and
sound.
is
type
bar
stops
The
the
a
stopclock
measurement
wave
b
is
speed
What
on
0.2 ms.
of
The
Explain
light
sound?
to
prism
b
What
c
The
is
the
sound
with
a
speed
of
source
frequency
sound
in
produces
of
a
1000 Hz.
the
steel
sound
in
air
is
The
wave
speed
of
10
What
both
is
wavelength
of
the
ii
diamond
greater
3
×
in
10
−1
m s
.
diamond?
disperses
extent
white
than
a
glass
and
a
and
have
index.
into
a
When
beaker
type
a
of
of
block
the
baby
exactly
of
baby
the
oil
oil
the
are
same
glass
the
is
block
sound
invisible.
Why
is
this?
air?
What
in
the
much
is
light
glass
refractive
340 m s
the
a
of
air
transparent
becomes
in
why
speed
in
would.
Borosilicate
placed
i
the
light
bar?
−1
sound
is
of
the
is
the
metal
wavelength
of
the
sound
bar?
103
11
A
ray
of
walled
shown
a
light
glass
in
the
Calculate
to
glass
passes
beaker
into
the
side
containing
of
a
water
thick-
13
as
angle
optical
with
diagram.
the
An
a
curved
of
refraction
at
the
air
a
as
Copy
boundary.
State
the
water
angle
of
the
incidence
at
the
glass
the
ray
boundary.
Calculate
glass
to
the
b
angle
water
of
refraction
at
Complete
the
diagram
What
the
centre
of
the
the
the
far
The
a
glass
fibre
is
diagram.
and
entry
from
1.60.
draw
into
the
the
fibre
path
until
of
it
end.
is
the
critical
angle
for
the
glass
to
boundary?
c
When
bending
showing
the
at
the
the
fibre
surface.
a
small
Explain
crack
why
this
may
ray
prevent
reaching
of
the
boundary.
ray
in
diagram
from
at
forms
d
constructed
index
to
air
c
is
shown
leaves
b
fibre
refractive
light
from
reaching
the
end
of
the
beaker.
fibre.
Normal
50°
Air
Water,
n = 1.33
Glass,
14
A
slide
projector
produces
a
magnified
image
n = 1.50
of
slides
The
12
Rays
of
light
are
shone
into
two
prisms,
slides
B,
as
shown
in
the
diagram.
Prism
A
of
a
standard
glass
with
which
1.50.
plastic
index
a
with
of
Prism
a
B
is
constructed
significantly
lower
from
the
critical
angles
refractive
for
both
of
the
prisms.
b
Use
the
results
complete
the
the
the
calculations
paths
until
the
to
rays
leave
blocks.
A
104
of
ray
14 cm
through
from
a
them.
has
a
focal
length
of
converging
8.0 cm.
Draw
a
ray
is
diagram
showing
how
the
produced.
a
1.2.
Calculate
placed
shone
refractive
image
index
is
is
a
constructed
are
light
A
lens
and
when
B
b
Describe
the
properties
of
c
Calculate
the
distance
d
Calculate
the
magnification
to
this
this
image.
image.
of
this
image.
15
The
lens
form
back
the
a
in
a
human
focussed
of
lens
the
eye.
and
the
eye
image
The
eye
is
on
retina
can
converging
the
lies
form
retina
5 cm
a
and
at
can
a
the
an
object
is
placed
a
behind
clear
minimum
three
showing
on
the
rays
how
on
the
a
copy
image
of
this
would
diagram
be
formed
retina.
image
b
when
Draw
Describe
the
properties
of
the
image
distance
formed.
of
20 cm
An
from
object
minimum
of
the
eye.
height
distance
4.0 cm
from
is
the
placed
lens
as
at
c
Calculate
the
magnification
d
Calculate
the
vertical
shown
simplified
ray
the
image.
size
of
the
image
on
in
the
the
of
this
retina.
diagram.
20 cm
5 cm
Retina
Object
105
4
Electricity
4.1
and
Static
Atoms
LEARNING
the
end
should
be
name
an
of
this
able


the
of
topic
you
(Figure
three
electric
4.1.1).
types
of
Protons
particles:
and
protons,
electrons
have
neutrons
a
property
charge.
to:
charged
particles
in
atom

describe
the
charged
particles
explain
composed
electrons
called


are
electricity
OUTCOMES
and
At
magnetism
forces
charging
are
nucleus
of
Neutrons
electrical
between

by
Protons
Atoms
small
to
be
atom.
also
positively
They
found
charged
cannot
bound
be
in
and
removed
the
nucleus
are
bound
into
the
easily.
but
have
no
charge.
are
and
are
positive
Very
are
Electrons
nucleus
induction.
said
the
negatively
can
be
neutral
charge
particles
and
charged.
removed
if
they
because
negative
They
are
they
charge,
are
found
provided
have
giving
a
the
outside
with
same
total
the
some
energy.
amount
charge
of
of
zero.
nucleus
Separating
charges
Most
are
+
materials
uncharged
because
they
are
composed
of
neutral
Proton
atoms.
When
some
materials
are
rubbed
together
the
frictional
forces
Neutron
can
cause
Because
move
Electron
This
electrons
the
from

protons
place
transfer
electrically
When
to
of
to
be
are
transferred
tightly
from
bound
in
one
the
material
nucleus
to
they
another.
cannot
place.
electrons
results
in
both
of
the
materials
becoming
charged:
extra
electrons
enter
an
object
the
object
becomes
negatively
charged.

Figure
4.1.1
The
structure
of
an
When
electrons
Rubbing
from
EXAM
is
movem
ent
from
place
caus
e
you
polythene
cloth
to
rod
the
with
it
has
extra
charged
because
it
has
fewer
a
Perspex
leaving
the
rod
rod
a
polythene
because
the
object
becomes
to
will
dry
cloth
rod.
The
electrons
cause
will
rod
and
electrons
positively
electro
ns
place
to
Mak
e
the
than
electrons
charged
cause
will
cloth
positive
becom
e
sure
that
Electrons
by
the
result
losing
as
move
the
move
become
(Figure
from
cloth
to
negatively
positively
4.1.2).
the
rod
negatively
to
the
charged.
Atoms
of
become
electrons
gained
positive
a
rod
result
losing
as
of
electrons
pro to
ns)
gained
+
movin
g
+
r
+
by
+
+
+
+
+ +
r
o
+
+
s
r
e
P
cloth
Dry
Figure
d
+
+
x
e
p
P
t
y
l
o
e
h
e
n
objec
ts.
o
of
Electrons
electro
ns
Dry
106
will
protons
to
and
electrons
become
+
out
charged.
become
that
a
describ
e
or
positively
Atoms
of
d
into
object
the
objec
ts
charge
d.
(no t
a
the
Rubbing
TIP
alwa
ys
an
charged
cloth
It
leave
atom
4.1.2
Charging
a
plastic
rod
cloth
cloth
Forces
between
charged
objects
+
Charged
particles
produce
a
force
on
each
other
in
a
similar
way
–
to
+
–
magnets:
–
+

Opposite
charges
attract
each
other.
(Positive
and
negative
–
charges
+
attract
each
Similar
repel
+
+
+
+
+
+
+
–
other.)
+

+
+
charges
positive
repel
each
other.
(For
example,
positive
–
–
+
charges
charges.)
a
The
charged
rod
is
held
near
the
sphere
ACTIVITY
Suspend
rods
of
different
materials
from
a
piece
of
cotton
–
so
that
they
can
rotate
freely.
Charge
up
the
rods
and
then
–
investigate
the
the
effects
suspended
of
placing
other
charged
rods
very
close
to
+
+
– +
+
–+
ones.
+
+
+
–
–
Electrons
from
–
Induced
charge
earth
flow
onto
sphere
A
neutral
placed
attracted
one
part
other
object
nearby
by
of
part
a
become
object
the
charged
4.1.3).
positively
the
of
can
(Figure
The
charged
to
object
when
electrons
rod
become
and
a
in
move
negatively
positively
charged
the
charged.
towards
charged
If
object
object
we
will
it
and
touch
is
b
be
The
sphere
is
earthed
briefly
causing
leaving
the
the
–
positively
–
charged
Earth.
area
then
Removing
electrons
to
electrons
the
can
original
distribute
move
charged
themselves
on
into
rod
the
the
will
object
then
object
from
cause
leaving
the
it
–
the
excess
–
–
charged.
–
This
The
process
same
is
referred
effect
can
some
uncharged
move
slightly
to
be
chalk
as
charging
seen
when
dust.
The
a
by
charged
electrons
in
rod
the
is
placed
dust
are
near
able
to
to
c
one
side.
and
This
cause
means
the
that
dust
the
particles
dust
to
particles
become
become
charged
attracted
on
to
The
rod
with
an
is
removed.
opposite
The
sphere
charge
to
the
is
left
rod.
the
Figure
charged
–
induction
4.1.3
Charging
by
induction
rod.
ACTIVITY
To
investigate
small
pieces
the
and
effect
place
of
induced
them
on
a
charge
desk.
cut
paper
Charge
up
a
into
KEY
very
plastic
rod
1
using
a
cloth
and
place
the
cloth
near
the
POINTS
Atoms
charge

Describe

Explain
what
why
happens
the
to
charged
the
rod
pieces
affects
of
the
have
no
overall
pieces.
paper.
an
uncharged
pieces
equal
and
of
because
they
number
of
contain
protons
electrons.
paper.
2
Electrons
between
can
be
objects
transferred
by
frictional
forces.
SUMMARY
QUESTIONS
3
1
A
a
student
door
an
2
handle.
electric
Dust
walks
along
A
shock.
particles
equipment
are
such
tiny
a
nylon
spark
Explain
is
television
and
produced
why
uncharged
as
carpet
this
but
then
and
reaches
the
out
student
to
attract
feels
they
often
Why
charged
each
similarly
happens.
screens.
Oppositely
other
charged
objects
while
objects
repel.
stick
does
to
electrical
this
happen?
4
Charges
neutral
can
be
induced
in
objects.
107
4.2
Electric
the
fields
Van
de
and
Graaff
generator
Electric
LEARNING
An
At
the
end
fields
OUTCOMES
of
this
topic
electric
field
experience
should
be
able
describe
an
electric
field
effect
on
field
charged
explain
how
generator
a
Van
region
of
space
in
which
a
charged
the
in
direction
the
field
of
force
(Figures
acting
4.2.1
on
and
a
positively
4.2.2).
particle
experiences
how
protected
buildings
from
A
charged
negatively
a
force
in
the
opposite
direction.
charges
To
explain
will
Graaff
Van
de
Graaff
generator
+

object
particles
de
separates
shows
placed
charged

a
force.
and
particle
its
a
to:
The

is
you
–
are
damage
Glass
dish
by
lightning.
Castor
oil
sprinkled
Conductors
with
semolina
powder
a
Figure
+
4.2.2
Demonstrating
an
electric
field.
The
particles
line
up
in
the
direction
+
+
+
of
the
field.
Charged
+
+
Lines
metal
of
+
+
force
sphere
+
The
Van
de
Graaff
generator
+
+
+
Rubbing
charge.
a
rod
To
with
a
produce
a
cloth
can
larger
only
separate
build-up
of
a
charge
small
a
amount
Van
de
of
Graaff
b
(VdG)

A
generator
large,
hollow,
can
be
metal
used
dome
(Figure
is
4.2.3).
insulated
from
the
ground
by
a
+
plastic

tower.
Inside
the
tower
passes
over
As
belt
two
a
rubber
rollers
belt
made
is
of
moved
by
different
an
electric
plastic
motor
and
materials.
c

the
from
the
negatively

Positively
comb
Figure
4.2.1
Electric
fields
charged
near
sphere,
b
a
a
the
c
a
point
negative
charge
point
the
the
lower
belt
roller
to
the
electrons
roller,
are
making
transferred
the
roller
charged.
are
ions
trapped
surface
of
are
on
the
attracted
the
belt
belt
to
as
it
positively
the
roller
moves
from
the
upwards.
metal
This
leaves
charged.
At
the
top
of
the
generator
the
positively
charged
belt
draws
and
electrons
charge
dome

As
Some
The
from
rubber
and
belt
of
effectiveness
on
through
of
charged
rotates,
charge
the
conditions.
water
dome
positively
positive
effects
weather
away
the
becomes
the
dome
108
of
a

positive
over
part
charged
but
outer
passes
inner
VdG
the
In
more
can
VdG
in
by
second
comb.
The
induction.
electrons
build
metal
up
are
on
removed
the
surface
from
of
the
the
dome.
generator
generator
humid
molecules
the
depends
conditions
the
air.
the
a
great
charges
deal
can
be
on
the
carried
move
+
+
from
ACTIVITY
+
Electrons
+
to
the
+
dome
rubber
Perspex
+
through
Metal
roller
a
receives
Your
and
stores
comb
+
+
a
charge
+
+
+
+
+
teacher
may
demonstrate
positive
VdG
generator.
+
metal
dome
+
belt
+
+
+
+

Place
your
hand
on
the
dome.
+
Electrons
+
+
+
will
be
stripped
+
+
+
from
your
body,
leaving
you
+
Insulating
column
positively
charged.
The
hairs
+
+
on
your
head
will
repel
each
+
Rotating
rubber
belt
other
and
apart
as
try
to
move
as
far
+
+
possible.
This
means
+
that
they
will
stand
on
end.
+
+

Once
you
have
been
charged
+
Motor
up,
touch
another
student.
+
+
They
+ +
Positive
the
ions
roller
are
and
drawn
trapped
an
towards
on
the
rubber
Polythene
belt
A
Van
de
Graaff
may
shock.
feel
Electrons
roller
their
4.2.3
you)
electric
from
Figure
(and
the
Earth
body
pass
and
into
through
you.
This
generator
movement
called
a
of
electrons
is
current.
Lightning

Lightning
is
a
very
large
spark.
Clouds
can
become
highly
charged
Observe
the
attaching
frictional
forces
acting
inside
them.
Droplets
of
water
and
ice
against
each
other
and
charges
are
separated.
Eventually
separation
is
so
large
that
a
lightning
bolt
is
of
bolt
is
often
a
flow
of
electrons
to
earth.
A
very
a
close
visible
current
is
produced
and
this
heats
the
air
around
it
a
bright
white
glow.
The
air
is
heated
so
quickly
that
a
thunder,
is
a
to
it.
Lightning
the

The
in
pointed
likely
up
in
that
have
end
the
Sometimes
current
two
the
charges
thick
are
placed
of
the
on
tops
conductor
building,
to
will
lightning
cause
metal
much
KEY
1
to
of
tall
buildings,
to
across
but
a
fire
cables
leak
be
will
or
or
allows
away
induced
into
the
air
charge,
pass
it
through
strike
even
bars
an
the
building
explosion.
that
allow
the
anyway.
Lightning
have
charged
objects.
electric
The
to
earth
safely
without
current
generating
from
4.2.4
Very
too
When
an
large
charge
electrical
fields
around
them
which
affect
Graaff
generator
electric
can
be
used
to
investigate
large
electric
amounts
can
in
be
the
of
created
by
atmosphere.
QUESTIONS
other
Why
does
lightning
strike
church
towers?
the
charge.
2
3
high
large
sometimes
of
in
point.
conductors
SUMMARY
Charges
effects
a
less
forces
de
up
struck.
heat.
Van
at
which
making
POINTS
A
curved
build
protect
1
2
is
evenly
ways:
Figure
lightning
are
produced.
building
the
could
may
This
lightning
conductors
building
builds

from
You
spark.
concentrations
Protection
generator
conducting
sound
surface
shockwave,
VdG
rapidly
spread
causing
the
large
because
electric
of
to
produced.
see
lightning
the
bringing
object
A
point
the
and
charge
a
crystals
dome
brush
effect
by
charges
current.
build
up
they
may
eventually
discharge
as
Why
shouldn’t
under
a
tree
in
you
a
stand
lightning
storm?
109
4.3
Uses
and
static
Dangers
LEARNING
the
end
of
this
topic
be
have
able
describe
static
electricity
already
a
associated
seen
resulting
that
in
the
build-up
lightning,
for
of
large
example.
charges
Even
can
small
be
sparks
or
to:
currents

electricity
you
dangerous,
should
of
OUTCOMES
You
At
of
dangers
range
with
of
can
sometimes
be
dangerous
or
damaging.
dangers
Refuelling
static
explosions
electricity
Large

describe
static
a
range
of
uses
for
Air
electricity.
electrical
resistance
(Figure
Car
tyres
can
a
explosion.
an
Aircraft
charge
can
as
build
they
up
fly.
spikes
designed
the
on
to
the
help
build-up
of
can
build
frictional
a
small
are
in
explosion.
car
up
on
forces
vehicles
cause
when
the
they
transfer
move.
of
electrons
prevent
allow
charge
to
can
as
in
even
flour
the
spark
can
have
car’s
can
ignite
been
metal
be
body.
If
produced.
petrol
vapour
designed
to
enough
When
and
help
cause
reduce
an
this
charge.
the
aircraft’s
are
to
a
spark
tyres
of
tanker
the
car
refuelled,
the
To
charge
the
build-up
aircraft
this
cause
tanks
build-up
connected
dissipate
moving
fuel
fuel
and
of
could
a
charge
together
by
cause
spark
a
a
could
the
build-
cause
aircraft
conducting
and
cable
to
safely.
explosions
when
there
is
dry
powder
in
the
air
mills.
static
These
Damage
thin
on
refuelling
such
4.3.1
car,
charge
Sparks
Figure
up
Modern
dangerous
of
transfer
builds
refuelling
up
other
4.3.1).
charge
When
charges
or
wing
to
electronics
are
reduce
Microprocessors
and
other
integrated
circuits
are
extremely
sensitive
static
to
static
electricity
and
can
be
ruined
if
there
is
a
build-up
of
charge.
electricity.
Uses
Static
of
static
electricity
pollution
and
electricity
can
in
also
spray
be
useful
painting
in
photocopiers,
in
reducing
air
surfaces.
Photocopiers
Photocopiers
on
Figure
4.3.2
This
is
electronic
connected
through
a
paper

A
rotating

A
bright

The

The
the
Earth
wristband
as
a
computer.
build-up
discharge
lead
the
110
instead
delicate
is
light
negative
reflected
in
of
static
charge
to
produce
images
is
negatively
shone
is
onto
reflected
charged
an
image
onto
the
by
a
brush.
on
a
sheet
charged
of
paper.
drum.
can
The
escape
areas
from
that
do
the
not
drum
in
receive
areas
light
that
receive
remain
the
damaging
circuitry.
charged.
This
means
that
the
charges
on
the
drum
are
body
through
of
charge
light.
Any
his
arranged
will
control
he
negatively
static
drum
light
bright
careful
4.3.3).
engineer
to
the
repairs
use
(Figure
paper.
in
the
same
pattern
as
the
image
on
the
original
sheet
of

A
positively
powder
is
charged
attracted
uncharged
‘toner’
to
the
powder
is
negatively
applied
charged
to
the
areas
drum.
but
This
not
to
the
areas.
Grid
of
charged

A
negatively
charged
piece
of
paper
is
pressed
against
the
rotating
wires
drum.

The
The
toner
paper
is
permanent
remaining
heated
copy
of
and
the
on
the
the
drum
toner
original
melts
is
attracted
onto
it
to
the
creating
paper.
a
image.
Earthed
metal
plate
Original,
face
Glass
down
plate
High
intensity
light
source
Figure
Charging
Powder
4.3.4
Electrostatic
precipitator
unit
unit
Drum
Heater
Paper
feed
Paper
out
Light
Charging
Powder
unit
unit
Paper
out
SUMMARY
1
What
to
a
QUESTIONS
charge
car
body
negatively
Figure
4.3.3
A
2
to
printers
create
the
operate
image
in
on
a
similar
the
way.
drum,
a
Instead
laser
of
beam
using
draws
reflected
a
pattern
any
image
can
be
Why
charged
phone
light
will
in
a
What
type
be
stations
chimney.
to
collect
and
past
earthed
To
produce
prevent
the
the
soot
soot
this
grid
plates
that
would
pollution
particles.
metal
metal
As
they
on
the
a
the
gain
side
normally
charged
soot
the
metal
particles
positive
of
escape
charge
chimney.
grid
rise
can
up
and
The
through
collected.
be
the
improve
it
is
This
the
used
for
are
soot
process
is
called
electrostatic
in
a
cell
station?
to
the
make
the
electronic
Figure
4.3.2?
used
attracted
can
to
KEY
POINTS
then
Static
electricity
can
damage
precipitation
components
cause
explosions.
quality
of
painted
surfaces
the
paint
can
be
Static
electricity
and
The
surface
is
oppositely
charged
and
so
the
whole
surface.
This
gives
a
very
even
is
used
in
charged
the
paint
coating
of
painting
and
is
reducing
to
use
painting
sprayed.
attracted
evenly?
materials
photocopying,
as
it
chimney
2
T
o
you
petrol
of
electronic
Improving
to
the
1
be
paint
pollution
engineer
Power
given
that
created.
wristband
air
stick
shouldn’t
should
Reducing
be
ensure
so
3
that
to
photocopier
droplets
Laser
should
pollution.
paint.
111
4.4
Electric
Current
LEARNING
the
end
of
this
topic


be
able
an
terms
charge
describe
metal
electric
the
a
of
electric
potential
current
in
Defining
current
in
a
current
in
an
The
size
in
unit
a
the
of
a
current
called
the
is
the
and
1
What
one
of
charge
coulomb
is
1
the
current
of
(A).
flow
The
of
flow
charge
relationship
Current
Electrical
circuit
a
the
a
=
of
charge
is
caused
and
is
this
is
normally
measured
written
as:
×
measured
time
using
or
a
Q
=
unit
It
called
the
coulomb
(A s).
a
wire
if
a
charge
of
360 C
is
transferred
in
It
=
360 C
=
=
charges
in
move
is
circuit
around
used
the
to
All
the
of
the
circuits
transfer
current
components.
circuit.
6.0 A
60 s
circuits
current
and
energy
EXAM
in
simple
wires
current
ampere second
in
t
In
=
are
=
Q
The
is
a
as
in
flow
is
of
pass
current.
to
used
the
In
an
electrical
electrons
not
complete
they
a
energy
current
electrons
components
up
through
as
whole
through
electrical
devices.
it
metal
travels
journey
around
releasing
them.
TIP
Conventional
impo
rtant
to
that
curren
t
positiv
e
to
when
circu
its.
conv
entio
nal
trave
ls
current
alwa
ys
Conventional
from
nega
tive
charge.
In
charges.
moving
This
in
current
circuits
the
means
the
is
described
energy
that
opposite
the
is
in
terms
actually
particles
direction
of
a
flow
carried
carrying
to
the
of
positive
by
a
of
positive
flow
charge
conventional
of
are
negative
actually
current.
discus
sing
Conductors
Metals
‘sea’
easy
are
of
for
Most
called
insulators
electrons
charges
other
carriers
and
composed
free
conductors
112
This
points.
minute?
I
even
two
EXAMPLE
Q
state
rate
ampere
transferred
WORKED
is
current.
current
Quantities
solution.
(C)
It
a
wire
describe
ionic
is
between
transfer
charge

charge
difference
to:
describe
of
flow
you
by
should
charge
OUTCOMES
The
At
and
current
and
of
a
lattice
move
can
freely
move
ions
about.
through
surrounded
This
metals
so
means
they
by
that
are
a
it
is
good
electricity.
solid
so
to
of
which
it
materials
is
insulators.
do
difficult
not
for
a
have
free
current
to
electrons
fl ow.
or
These
other
charge
materials
are
Semiconductors
Some
can
materials
conduct
lie
between
under
semiconductors.
conduct
such
one
as
can
be
the
Silicon
altered
germanium.
direction
enough.
This
Current
and
in
is
if
a
extremes
atoms
of
semiconductors
the
potential
in
diodes
of
conductivity.
These
semiconductor
adding
used
ionic
two
circumstances.
is
by
Some
only
effect
the
right
and
other
are
its
They
classed
ability
as
to
semiconductors
made
difference
and
are
to
conduct
across
it
is
in
high
transistors.
solutions
ACTIVITY
When
sodium
chloride
is
dissolved
in
water
an
ionic
solution
is
Test
a
range
of
materials
to
+
formed.
This
contains
two
different
types
of
ions:
Na
and
Cl
see
If
electrodes
both
of
these
difference

The
seen
ions
and
sodium
on
the
two
can
and
flow
connected
because
of
to
the
a
battery,
potential
electrodes.
positively
When
and
reach
This
or
if
they
and
the
rapidly
hydrogen
so
are
attracted
electrode
reacts
gas
and
they
with
so
the
to
simple
lamp
ions
and
process
solution.
or
can
an
use
a
ammeter
the
obtain
water
bubbles
to
can
be
are
negatively
When
form
they
chlorine
charged
reach
the
and
are
attracted
electrode
they
to
lose
the
an
gas.
is
called
electrolysis
and
can
be
carried
out
on
scale
to
produce
Electrolysis
of
useful
other
chlorine
ionic
gas
solutions
and
can
sodium
produce
the
material
in
the
circuit
an
to
industrial
conductors
You
4.4.1).
Place
This
are
insulators.
(Figure
charged
they
sodium.
hydroxide
electrode.
electron
solution
particles
are
form
the
electrode.
chlorine
positive
in
the
electrode.
electrons
The
charged
sodium
form
placed
between
negative

are
find
out
if
it
can
conduct
electricity
hydroxide
other
useful
Figure
4.4.1
A
simple
conduction
test
chemicals.
SUMMARY
QUESTIONS
1
complete
Copy
and
T
able
4.4.1
relating
current,
charge
and
time.
T
able
4.4.1
Current/A
2.5
0.05
KEY
Charge/C
100
Time/s
POINTS
0.2
40
300
1
The
current
caused
2
A
current
How
3
of
much
Molten
150 mA
charge
electrolytes
flows
has
through
been
can
also
a
circuit
for
4
from
minutes.
a
transferred?
conduct
electricity.
Molten
lead
2
a
by
a
in
a
flow
negative
positive
metal
of
wire
is
electrons
terminal
to
terminal.
Conventional
current
is
a
2+
bromide
when
contains
electrodes
connected
to
a
Pb
are
and
placed
battery.
Br
in
ions.
Explain
molten
lead
what
happens
bromide
and
flow
a
of
positive
positive
negative
charge
terminal
to
from
a
terminal.
113
4.5
Electrical
energy
and
transformations
Potential
LEARNING
Potential
At
the
end
of
this
topic
be
able
charged
calculate
the
is
will
the
cause
move
to
a
of
the
movement
position
where
it
of
will
charge.
have
less
energy
and
so
will
move
to
a
‘lower’
point
in
an
electric
field.
potential
This
difference
particle
to:
potential

difference
you
A
should
difference
OUTCOMES
between
is
a
little
like
a
mass
in
a
gravitational
field.
As
the
mass
falls
two
through
the
gravitational
field
it
loses
potential
energy.
The
energy
points
loss

calculate
the
on
the
distance
moved
through
the
field,
the
strength
energy
of
transferred
depends
by
an
the
field
and
the
size
of
the
mass.
In
electricity
the
energy
change
electrical
depends
on
the
size
of
the
charge
and
the
potential
difference
it
device.
moves
through.
Potential
difference
is
therefore
defined
energy
potential
difference
by
the
equation:
transferred
=
E
or
V
=
charge
WORKED
How
EXAMPLE
much
through
a
energy
is
potential
Q
1
transferred
difference
when
of
a
charge
of
3.2 C
passes
5.0 V?
E
V
=
Q
E
In
=
VQ
circuits
higher
the
5.0 V
component
measured
EXAM
is
in
cal
measu
red
watt
way
is.
16 J
of
force
by
an
are
battery
and
and
the
power
force
power
called
the
source
voltage
referred
to
is
across
difference
simply
an
at
as
the
electrical
(p.d.).
Both
are
voltages.
(W)
as
One
powe
in
in
r
the
the
is
Just
unit
same
mecha
nica
l
watt
is
one
as
device
the
in
is
mechanical
the
rate
definitions
of
at
energy
which
it
potential
powe
r
transfer,
transfers
difference
the
power
energy.
and
current
E
V
=
of
This
an
can
as
electrical
be
linked
follows:
E
and
Q
=
It,
therefore
V
=
joule
It
second
.
E
IV
=
E
and,
as
power
is
defined
t
Electrical
114
is
power
Q
per
supply
electromotive
potential
often
or
terminal.
electrical
(e.m.f.)
called
and
a
negative
difference
usually
volts
=
TIP
Electrical
Electri
the
produced
electromotive
3.2 C
terminal
than
potential
voltage
×
positive
potential
Voltage,
The
=
power
is
measured
by
P
=
,
t
in
watts
(W).
P
=
IV
to
WORKED
How
with
EXAMPLE
much
a
P
=
IV
=
0.5 A
E
=
Pt
=
3.0 W
Electrical
Electrical
some

transferred
×
6.0 V
×
20 s
=
=
of
by
a
6.0 V
bulb
and
a
in
20 s
if
current
it
of
operates
0.5 A?
3.0 W
60 J
transformations
energy
Electrical
can
motors
a
Electricity
wide
can
fluorescent

is
difference
be
transformed
in
many
useful
ways.
Here
are
examples:
allowing

energy
potential
2
transform
range
be
of
electrical
objects
converted
into
to
energy
into
kinetic
energy,
move.
light
using
filament
bulbs,
LEDs
or
tubes.
Loudspeakers
Conservation
convert
of
electrical
energy
to
sound.
energy
Figure
4.5.1
Light
or
Electrical
energy
is
very
useful
as
it
can
be
transferred
and
emitting
fluorescent
but
most
of
the
production
of
electricity
relies
on
more
so
fuels.
These
reducing
resources
using
their
by
fuels
use
using
alternative
are
is
only
available
important.
more
efficient
sources
of
We
in
can
electrical
energy
where
limited
quantities
conserve
efficient
than
burning
filament
fossil
are
transformed
much
easily
diodes
tubes
some
of
bulbs.
and
these
devices
(Figure
4.5.1)
possible
(Figure
4.5.2).
or
by
ACTIVITY
Use
a
voltmeter
potential
power
and
difference
an
ammeter
across
a
to
lamp.
measure
Use
your
the
current
readings
to
in
and
find
its
rating.
Figure
4.5.2
Electricity
using
can
be
generated
photovoltaic
solar
cells.
SUMMARY
1
What
a
2
is
one
of
charge
4.0 W
potential
40 mC
1
12.4 A
of
an
and
is
and
electrical
potential
transferred
operating
device
which
difference
when
voltage
a
of
of
torch
operates
with
12 V?
with
6.0 V
a
power
operates
for
minute?
What
KEY
power
of
much
rating
3
the
current
How
QUESTIONS
with
difference
10 J
of
is
required
to
provide
a
charge
of
energy?
POINTS
The
potential
difference
across
a
component
is
defined
by
E
V
=
Q
2
The
power
of
an
electrical
device
is
given
by
P
=
IV
115
4.6
Simple
circuits
and
components
A
LEARNING
a
At
the
end
should
be
simple
circuit
of
this
able
topic
battery
or
draw
simple
containing
power
of
a
source
supply),
of
electromotive
connecting
leads
and
force
some
(a
cell,
electrical
to:
circuit
a
a
components.
you
Circuit

consists
OUTCOMES
range
diagrams
diagrams
of
Drawing
realistic
diagrams
of
the
components
is
not
necessary
and
components
can

interpret
circuit
diagrams
them
to
construct
confusing,
so
a
standard
set
of
symbols
is
used.
and

use
be
The
same
symbols
are
used
around
the
world
allowing
all
engineers
real
to
understand
them.
circuits


explain
why
a
standard
set
A
circuit
diagram
components
symbols
is
used
for
4.6.1
Component
Standard
very
the
important
connections
between
clearly.
circuits.
The
T
able
shows
of
electrical
Symbol
key
circuit
are
shown
in
T
able
4.6.1.
symbols
Use
earth
symbols
point
Component
of
lowest
wires
Symbol
passing
Use
indicates
potential
wires
or
that
are
not
connected
together
cell
provides
an
lamp
or
bulb
transforms
electromotive
electrical
energy
or
force
battery
in
the
provides
circuit
an
into
voltmeter
light
measures
electromotive
the
force
difference
in
the
circuit
potential
between
two
points
d.c.
power
provides
supply
+
an
ammeter
measures
electromotive
current
force
point
at
the
that
–
in
the
circuit
in
the
circuit
a.c.
power
supply
provides
a
galvanometer
small
force
in
the
connects
circuit
or
disconnects
semiconductor
allows
diode
only
components
junction
indicates
wires
116
that
are
very
currents
or
electromotive
switch
measures
changing
of
electrolytic
cell
current
in
the
direction
arrow
produces
a
precise
connected
electromotive
together
force
Component
Symbol
Use
fuse
Component
melts
off
and
the
cuts
circuit
Symbol
Use
loudspeaker
transforms
if
electrical
energy
or
the
current
is
too
into
sound
large
fixed
resistor
reduces
the
transformer
changes
current
in
a
of
an
branch
of
a
current
the
p.d.
alternating
or
circuit
variable
resistor
a
resistor
value
can
manually
electric
motor
whose
generator
transforms
GEN
be
energy
altered
kinetic
into
electrical
energy
transforms
electrical
into
energy
kinetic
energy
ACTIVITY
Draw
a
SUMMARY
circuit
diagram
for
the
two
circuits
in
Figure
4.6.1.
1
Draw
the
diagram
shown
Figure


draw
Start
Use
any

correct
for
in
the
circuit
two
Figure
circuits
4.6.2.
4.6.1
Figure
To
QUESTIONS
a
by
a
circuit
drawing
ruler
other
Work
clearly
to
the
draw
straight
around
the
follow
cell,
all
of
these
battery
the
simple
or
power
connecting
4.6.2
rules:
2
supply.
leads
and
wires
A
student
has
drawn
diagram
poorly
Describe
and
mistakes
the
a
(Figure
circuit
4.6.3).
and
correct
the
lines.
circuit
in
a
logical
order.
Start
from
student
has
the
made.
positive

Draw
one
terminal

If
the
If
any
on
mark
using
should
at
a
time
working
towards
the
negative
battery.
has
moving
circuit
There
KEY
1
the
necessary
the

component
of
circuit
before

terminal.
be
branches
to
the
the
direction
small
no
then
complete
one
branch
conventional
current
next.
of
the
on
arrows.
gaps
in
the
Figure
4.6.3
circuit.
POINTS
Circuit
diagrams
show
the
connections
between
components
clearly.
2
Standard
symbols
must
be
used
for
circuit
diagrams.
117
4.7
Series
and
parallel
circuits
There
LEARNING
are
(Figure
At
the
should

end
be
current
of
this
able
describe
two
categories
of
circuits:
series
and
parallel
OUTCOMES
the
in
topic
4.7.1).
behaviour
you
provided
to:
behaviour
series
and
of
to
To
analyse
the
the
current
these
in
the
circuits
circuit
we
need
and
the
to
understand
changes
in
the
energy
components.
of
parallel
Series
circuits
circuits
Series

describe
the
difference
parallel
potential
in
series
circuits
pathway
are
the
connecting
simplest
the
type
positive
of
and
circuit.
There
negative
is
only
one
terminals.
and
Understanding
circuits.
In
of
the
circuit
electrons,
current
the
current
moving
in
is
series
circuits
composed
through
the
of
wires.
a
flow
The
of
charge,
electrons
in
pass
the
form
through
a
each
component
They
can
also
cannot
enter
This
only
and
stay
at
means
in
the
that
components
in
turn
release
in
a
they
of
cannot
the
component.
same
the
but
some
The
created
they
same
or
carry.
destroyed.
The
number
electrons
has
to
leave
all
of
as
rate.
current
series
be
energy
with
must
each
be
exactly
the
same
in
the
other.
b
Understanding
The
or
source
a
power
used
but
through.
circuit
4.7.1
Circuit
bulbs
b
a
in
shows
series
shows
parallel
a
and
an
this
principle
passing
When
they
In
is
transfer
in
force
circuit
in
the
description
the
through
the
difference
same
the
electrons
some
of
cell
for
all
gain
move
the
we
series
will
can
be
assume
a
a
cell,
cell
is
a
battery
being
sources.
potential
through
energy
circuits
a
they
energy
as
component
gained
they
in
when
pass
the
passing
two
resistor
with
electromotive
supply.
the
Electrons
Figure
of
potential
circuit
in
electric
through
the
electrons
started
cell.
will
with,
After
have
the
before
moving
same
they
through
amount
passed
of
all
of
the
components
potential
through
the
energy
as
the
they
first
cell.
motor.
As
energy
the
as
same
they
gained
difference
EXAM
Appl
y
TIP
the
anal
ysis
stag
e
you
a
at
will
wide
force
a
rules
of
of
be
able
conserved
the
around
when
cell.
the
This
the
they
means
circuit
electrons
pass
must
have
through
that
the
match
sum
the
to
the
of
lose
exactly
components
the
potential
electromotive
circuits
one
and
to
be
energy
cell.
Parallel
circuits
have
branches
where
the
current
can
divide
and
re-join.
so lve
Understanding
of
of
from
drops
the
Parallel
rang
e
always
circu
it
caref
ully,
time,
must
amount
current
in
parallel
circuits
circu
it
problem
s.
The
of
current
that
junction.
junction
must
junction.
118
into
They
any
junction
This
be
the
can’t
is
must
because
same
stay
at
as
the
the
the
exactly
rate
rate
of
junction.
match
of
the
electrons
electrons
current
out
entering
leaving
the
the
If
current
divides
recombine
or
other
to
when
power
potential
Electrons
as
What
the
difference
is
circuit
current
shown
each
have
different
the
current
in
to
lose
the
leaving
must
the
before
current
entering
parallel
branch
path
then
current
cell,
it.
circuits
be
same
they
will
the
the
same.
amount
of
energy
re-join.
1
and
in
match
The
difference
path
a
EXAMPLE
the
to
branches
re-join.
across
one
following
WORKED
has
potential
following
electrons
different
branches
supply,
Understanding
The
follow
the
potential
Figure
difference
across
the
bulbs
in
4.7.2?
12.0 V
The
potential
branches
difference
must
electromotive
be
the
force
across
same
of
the
as
the
the
battery.
E
4.0 A
This
means
across
there
bulbs
D
is
a
and
The
current
from
The
current
into
p.d.
of
12.0 V
E.
the
battery
bulb
D
is
4.0 A.
is
3.0 A
and
E
must
be
3.0 A
D
so
the
current
into
bulb
Figure
SUMMARY
QUESTIONS
1
of
4.7.2
1.0 A.
Sketch
all
circuits
bulbs.
More
A
complex
circuit
does
not
combinations
to
the
of
circuits
have
both.
appropriate
to
be
The
parts
and
purely
rules
of
the
series
for
or
parallel
parallel.
and
Many
series
are
circuits
2
apply
Find
Z
in
can
Include
the
Figure
equal
involve
five
parallel
circuits.
current
across
possible
series,
combined
p.d.
circuit.
that
the
the
in
and
the
resistors
4.7.4.
X
and
Y
Y
and
are
resistances.
8.0 V
WORKED
The
circuit
series
each
The
EXAMPLE
shown
elements.
of
the
This
Figure
Find
the
4.7.3
current
contains
and
both
potential
parallel
and
difference
across
2.0 A
from
the
means
X
0.5 A
bulbs.
current
2.0 A.
in
2
battery
that
the
Y
W
is
12.0 V
Z
current
1.5 V
through
so
must
bulb
the
P
must
current
be
2.0 A
through
and
2.0 A
Figure
bulb
4.7.4
Q
S.
The
total
current
Q
and
bulb
R
through
bulb
1.5 A
so
the
must
current
be
2.0 A
through
R
and
must
S
P
be
R
KEY
2.0 A
The
1.5 A
p.d.
same
is
−
as
=
across
the
0.5 A.
bulb
p.d.
Q
must
across
bulb
be
R
4.0 V
the
so
it
Figure
1
This
total
4.7.3
of
p.d.
means
12.0 V
−
The
is
4.0 V
.
The
POINTS
5.0 V
around
that
5.0 V
the
−
the
p.d.
4.0 V
circuit
across
=
3.0 V
.
must
bulb
S
be
12.0 V
.
must
be
2
current
equal
to
into
the
any
junction
current
out
it.
The
potential
around
circuit
any
is
difference
closed
loop
in
a
zero.
119
4.8
Cells
Chemical
LEARNING
the
end
of
this
topic
be
electromotive
able
describe
how
cells
by
force
chemical
(e.m.f.)
required
reactions
to
between
drive
acids
a
current
and
can
metals.
be
Each
cell
two
produce
or
electrodes:
the
positive
and
the
negative.
are
restricted
in
the
size
of
the
current
they
can
provide
by
their
an
internal
electromotive
terminals
and
Cells
batteries
cells
to:
has

in
you
produced
should
reactions
batteries
OUTCOMES
The
At
and
resistances
which
are
due
to
their
physical
and
chemical
force
composition.

distinguish
between
primary
A
and
secondary
battery
other.

draw
a
diagram
to
a
secondary
The
simply
e.m.f.
a
of
collection
the
of
battery
cells
will
placed
be
the
in
sum
series
of
with
the
each
e.m.f.s
of
the
show
cells,
how
is
cells
cell
can
assuming
all
of
the
cells
are
placed
the
same
way
around.
be
recharged.
Primary
In
a
primary
cannot
Metal
(positive
place,
cap
cell
Insulator
rod
be
the
cell
the
reversed.
cell
chemical
This
cannot
reaction
means
be
that,
recharged
which
once
and
the
produces
reaction
reused.
There
the
has
are
e.m.f.
taken
several
contact)
types
Carbon
cells
and
of
primary
(Figure
cells.
One
common
example
is
the
zinc–carbon
dry
4.8.1).
seal
(+)
In
Positive
Zinc
(–)
a
zinc–carbon
cell
a
metal
case
of
zinc
acts
as
the
negative
case
+
electrode
and
(outer
current
card
metal
or
electrode
a
carbon
rod
acts
as
the
positive
electrode.
A
reaction
jacket
occurs
collector
and
between
the
zinc
and
carbon
and
an
ammonium
chloride
removed)
paste
Paste
and
this
reaction
produces
an
e.m.f.
of
1.5 V
initially.
of
ammonium
chloride
Zinc–carbon
cannot
cells
provide
have
large
a
relatively
currents,
high
the
internal
maximum
resistance
being
and
around
so
1 A.
they
This
solution
means
that
they
are
not
suitable
for
providing
energy
to
high
power
(electrolyte)
devices.
Negative
–
Paper
contact
separator
Manganese (IV) dioxide
(reduces
the
internal
Chemical
they
4.8.1
A
reactions
not
zinc–carbon
cell
become
replaced
A
a
but
The
car
a
in
most
battery
is
a
that
zinc–carbon
the
cells
cells
even
discharge
when
over
It
can
be
can
also
corrode
inside
time
equipment
if
not
In
the
cell
an
so
cells
a
the
can
cell
be
of
e.m.f.
have
a
be
reaction
2 V
.
low
forced
cell
(positive
12 V
internal
to
a
is
to
produce
reverse
to
the
by
cell.
an
applying
This
means
repeatedly.
is
the
between
Inside
of
reaction
direction
recharged
e.m.f.
very
can
opposite
plates
of
chemical
secondary
the
oxide
total
on
reaction
in
type
this
lead
relies
lead–acid
lead
plates
electrode)
car
battery
and
six
cell
used
recharged.
currents
required
to
power
a
in
(negative
dilute
cells
are
sulfuric
placed
produced.
resistance
and
can
provide
the
secondary
large
cell.
time
and
and
Lead–acid
car
also
common
produces
series
They
difference
batteries.
acid
cell
secondary
electrode)
120
inside
means
cells
this
potential
that
A
place
This
useless.
secondary
e.m.f.
4.8.2
take
use.
regularly.
Secondary
Figure
in
resistance)
and
Figure
are
starter
motor.
They
also
contain
significant
sulfuric
quantities
acid
WORKED
A
car
to
P
=
I
=
lead
and
so
are
very
heavy
and
have
corrosive
EXAMPLE
battery
required
of
inside.
produces
turn
a
an
starter
e.m.f.
motor
of
12 V
.
with
a
What
power
size
current
rating
of
is
4.8 kW?
IV
3
P
4.8
×
Recharging
single
battery
400 A
12 V
secondary
lead–acid
with
W
=
V
A
10
=
an
cell
cells
can
e.m.f.
be
recharged
greater
than
using
4.0 V
.
This
a
power
applied
supply
e.m.f.
is
or
a
greater
Cell
2.0 V
being
recharged
than
the
reaction
A
car
e.m.f.
to
the
happen
battery
This
provides
and
so
the
of
is
a
in
cell
to
the
reverse
recharged
reverse
battery
by
be
an
e.m.f.
remains
recharged
to
fully
and
direction
(Figure
alternator
the
will
driven
battery
while
force
the
chemical
4.8.3).
by
the
the
car
car
is
engine.
in
motion
charged.
Recharging
power
4.0 V
supply
ACTIVITY
Figure
4.8.3
Recharging
cell.
Use
a
lead–acid
condition
of
equipment
cell
the
to
to
power
plates
measure
over
the
a
low
several
current
voltage
hours
and
bulb.
and
e.m.f.
Monitor
use
data
provided
the
electrode
logging
by
the
Note
cell.
supply
Recharge
the
cell
the
cell
behave
using
in
the
a
power
same
supply
and
repeat
the
test.
Does
to
travel
cell
SUMMARY
1
Draw
a
A
table
be
KEY
1
an
the
the
in
the
to
negative
cell
is
negative
power
the
current
opposite
that
when
the
discharging.
summarising
the
characteristics
of
primary
and
cells.
zinc–carbon
with
to
of
the
the
QUESTIONS
secondary
2
is
lead–acid
forcing
direction
way?
of
connected
electrode
a
how
e.m.f.
provided
battery
of
by
provides
1.5 V
.
this
What
is
a
maximum
the
current
maximum
of
power
1.2 A
that
can
cell?
POINTS
Cells
produce
an
electromotive
force
through
a
chemical
reaction.
2
Primary
cells
use
irreversible
reactions
and
cannot
be
recharged.
3
Secondary
cells
use
reversible
reactions
and
can
be
recharged.
121
4.9
Resistance
Using
LEARNING
electrical
Electrical
At
the
end
of
this
topic
meters
be
able
use
an
ammeter
calculate
used
to
meters
measure
must
be
both
placed
current
and
carefully
in
potential
order
to
operate
(Figure
4.9.1).
An
ammeter
is
used
to
measure
the
current
at
a
point
in
a
circuit.
correctly
The

the
and

voltmeter
but
to:
correctly

are
you
difference
should
meters
OUTCOMES
the
resistance
of
current
has
to
pass
through
the
ammeter
for
its
magnitude
a
to
be
measured
and
so
the
ammeter
needs
to
be
placed
in
series
component
with

state
Ohm’s
conditions
law
and
under
could
the
which
the
other
reduce
components.
the
current
Placing
and
so
the
ammeter
ammeters
need
in
to
this
way
have
very
low
resistances.
it
applies.

A
voltmeter
in
it
the
is
to
measures
circuit.
It
measuring
have
very
through
has
the
high
to
the
be
potential
placed
potential
resistance
in
difference
parallel
difference
so
that
across.
almost
between
with
no
the
two
points
components
Voltmeters
current
will
need
pass
them.
Resistance
In
4.8
it
was
mentioned
restricts
the
current.
Metals
high
The
the
current
in
wires
that
them.
have
cells
All
low
have
an
resistance
resistance
current
of
a
component
through
is
while
defined
Resistances
an
ammeter
voltmeter
current
to
are
and
a
have
very
as
the
ratio
of
the
p.d.
to
or
R
=
measured
in
a
I
unit
called
the
ohm
(Ω).
the
EXAMPLE
1
bulb.
What
is
current
the
of
resistance
2.5 A
V
R
=
Ohmic
A
was
The
of
a
a
length
p.d.
of
of
metal
3.0 V
is
wire
across
if
there
is
a
it?
3.0 V
=
1.2 Ω
2.5 A
conductors
simple
physical
when
=
I
metal
wire
properties
discovered
current
potential
by
will
and
have
Georg
through
difference
a
a
constant
conditions
Ohm
conductor
across
do
and
is
so
∝
resistance
not
is
change.
called
directly
it
I
122
rods
a
p.d.
WORKED
across,
glass
to
and
measure
through,
which
resistance
V
=
current
Using
a
it:
p.d.
4.9.1
resistance
have
resistance.
resistance
Figure
internal
components
V
as
long
This
Ohm’s
as
its
relationship
law:
proportional
to
the
The
constant
which
obey
of
proportionality
Ohm’s
conductors.
For
some
remain
constant
classed
as
Resistor
In
with
a
This
to
resistance
see
in
of
resistance)
the
4.10)
the
are
wire.
called
resistance
and
their
Materials
ohmic
does
not
behaviour
is
sometimes
difference
other
resistors
EXAMPLE
are
used
to
limit
components
usually
small
the
maximum
from
being
devices
size
of
damaged
placed
in
by
series
of
it
is
6.0 V
.
to
2
current
when
diode
is
components.
maximum
0.2 A,
the
the
components
will
prevents
The
other
WORKED
The
you
resistor
currents.
the
other
is
constant
components
current.
large
(as
(have
‘non-ohmic’.
circuits
the
law
ACTIVITY
through
operated
What
ensure
that
a
by
resistor
the
diode
a
needs
battery
should
current
be
can
to
be
supplying
placed
never
be
restricted
Build
a
variable
in
potential
series
greater
with
a
simple
brightness
than
circuit
resistor
of
a
so
using
that
bulb
a
the
can
be
adjusted.
0.2 A?
V
R
=
6.0 V
=
=
I
Variable
Variable
the
resistors
resistors
circuit
altered
30 Ω
0.2 A
by
can
(Figure
also
4.9.2).
turning
a
dial
be
The
or
used
to
adjust
resistance
moving
a
of
the
the
sliding
current
variable
contact.
in
a
branch
resistor
In
can
of
be
laboratories
Fixed
variable
Other
A
are
often
called
dependent
the
light
level
resistor
it
is
(LDR)
exposed
to.
has
a
LDRs
resistance
have
low
which
varies
resistance
to
light
build
when
Variable
resistor
Light-dependent
it
and
light
gets
Temperature
very
high
sensors
and
resistance
switch
on
in
low
light.
lighting
They
systems
can
Thermistor
be
4.9.2
used
automatically
dark.
sensitive
resistance
changes
to
heating
resistors
depending
are
on
called
the
thermistors
temperature.
and
They
their
can
be
used
KEY
control
resistor
in
Figure
bright
resistor
rheostats.
resistors
light
with
resistors
or
cooling
POINTS
systems.
1
The
resistance
component
is
of
a
defined
by
the
V
equation
SUMMARY
What
=
I
2
1
R
QUESTIONS
current
will
there
be
in
a
12 V
bulb
with
a
resistance
Ohmic
conductors
have
a
of
fixed
resistance
while
the
1.5 Ω?
resistance
2
Explain
how
brightness
resistance
a
of
variable
a
and
bulb
resistor
using
current.
the
can
be
ideas
used
of
to
adjust
potential
the
difference,
of
conductors
to
factors
non-ohmic
changes
like
light
due
or
temperature.
123
4.10
Investigating
and
current
potential
difference
characteristics
Investigating
LEARNING
To
At
the
end
should

be
describe
the
the
resistance
of
components
OUTCOMES
of
this
able
investigate
the
behaviour
of
different
components
we
measure
the
you
current
in
the
component
For
investigation
when
different
voltages
are
applied
to
it.
to:
how
current
topic
to
and
this
variable
measure
is
the
used
circuit
to
shown
control
the
in
Figure
current
4.10.1
in
the
is
used.
The
wire.
voltage
Once
characteristics
resistor
of
a
range
the
data
is
collected
a
current–voltage
(or
I
V)
graph
can
be
of
drawn
and
this
reveals
the
characteristic
of
the
resistance.
The
shape
components
of

describe
metallic
lamps,
the
characteristics
conductors,
filament
semiconductor
the
ionic
is
referred
to
as
the
I
V
characteristic
of
the
component.
Metal
wires
diodes
As
and
graph
of
shown
in
4.9
a
metal
wire
is
an
ohmic
conductor.
We
can
see
solutions.
evidence
for
produced
wire
by
this
in
the
graph
demonstrating
finding
the
(Figure
that
gradient
I
∝
of
gradient
=
to
graph
the
can
Test
also
shows
resistance.
travel
Filament
just
This
as
∴
the
is
we
as
in
R
the
is
resistance
of
the
gradient
direction
would
either
find
line
=
V
that
freely
can
straight
1
=
Δx
The
We
A
graph:
I
Δy
Cell
V.
this
4.10.2).
of
the
expect
current
because
is
not
the
relevant
electrons
direction.
lamps
component
Filament
gas.
does
not
constant
Figure
4.10.1
Finding
the
voltage
characteristics
are
there
is
increase
just
as
simply
a
very
small
significantly
for
an
thin
current
ohmic
metal
in
and
the
so
wires
kept
filament
the
inside
its
resistance
an
of
the
filament
conductor.
of
the
current
increasing
electrons
line
to
to
increases
V
+I
is
The
the
travel
curve
relationship
sufficiently
it
will
cause
the
wire
to
heat
resistance
of
through
hot
below
I
required
∝
to
V
that
no
Semiconductor
for
for
an
longer
increase
characteristic
a
a
the
the
wire
wire.
ohmic
holds,
as
as
This
it
is
more
causes
conductor
a
difficult
the
(Figure
progressively
for
the
characteristic
4.10.3).
larger
The
increase
in
current.
filament
lamp
is
symmetrical.
diodes
+V
V
The
conduction
from
that
in
and
the
mechanism
metals
characteristic
and
graph,
currents
as
is
in
beyond
shown
involved
semiconductor
are
in
the
scope
Figure
usually
diodes
of
4.10.4,
very
small
this
has
so
a
is
very
course.
an
different
The
unusual
recommended
When
4.10.2
a
for
negative
the
investigation.
voltage
is
applied
the
diode
has
a
very
large
Current–voltage
resistance
characteristic
conductor
of
an
and
therefore
there
is
a
very
small
current,
ohmic
microamps.
The
diode
is
said
to
be
‘reverse
biased’.
I
V
shape
microammeter
– I
124
is
component
up,
Figure
inert
temperature
current–
When
a
lamps
When
a
few
is
In
the
with
forward
almost
bias
no
direction
current
at
the
all
for
diode
has
voltages
an
up
even
to
higher
0.7 V
.
resistance
Beyond
this
Current
value
+I
voltage
the
diode
becomes
a
much
better
conductor
allowing
for
larger
ohmic
onductor
currents
Ionic
through.
solutions
+V
V
To
investigate
need
to
be
the
I
placed
V
characteristics
into
the
solution
of
a
ionic
fixed
solutions
distance
two
electrodes
Lower
value
apart.
by
The
resulting
ohmic
graph
conductor.
shows
that
However,
the
the
ionic
solution
resistance
is
behaves
large
when
as
current
caused
increasing
R
an
compared
– I
to
metal
Instead
wires
of
and
it
electrons
depends
there
are
on
the
two
concentration
different
charge
of
the
solution.
carriers,
for
Figure
4.10.3
Current–voltage
2+
example,
copper
ions
(Cu
)
moving
to
the
cathode
and
sulfate
ions
characteristic
of
a
filament
2−
(SO
)
moving
to
the
anode.
lamp
4
ACTIVITY
+I /mA
Use
an
the
method
ionic
described
solution
resistance
of
the
over
an
to
investigate
extended
solution
the
period
of
characteristics
time.
How
of
does
Near
ohmic
the
Forward
change?
bias
V
+V
0.7 V
KEY
1
POINTS
Ohmic
conductors
(wires
and
ionic
solutions)
have
constant
– I / μA
resistances.
2
The
resistance
of
filament
lamps
increases
at
high
currents
Figure
as
4.10.4
Current–voltage
characteristic
the
temperature
of
the
wire
of
semiconductor
3
Semiconductor
threshold
diodes
voltage
and
SUMMARY
QUESTION
1
A
class
of
students
graphs
of
the
T
able
have
low
very
and
high
resistance
investigated
current
a
increases.
a
voltage
resistance
beyond
range
of
below
diode
a
it.
components
characteristics
and
collecting
identify
the
the
data
shown
in
T
able
4.10.1.
Plot
component.
4.10.1
Component
Voltage
A
/ V
Current
−5
−4
−3
−2
−1
0
1
2
3
4
5
−0.8
−0.76
−0.69
−0.48
−0.24
0
0.24
0.48
0.69
0.76
0.8
−1
−0.8
−0.6
−0.4
−0.2
0
0.2
0.4
0.6
0.8
1
−0.01
−0.01
−0.01
−0.01
−0.01
0
0
0
0.2
2.1
4.2
/A
Component
Voltage
B
/ V
Current
/mA
125
4.11
Circuit
Most
LEARNING
the
end
should
be
of
this
able
topic
you
resistive
find
in
the
series
resistances
find
the
resistor
resistance
and
of
to
fully
in
of
components
analyse
series
the
and
usually
parallel.
We
including
can
groups
combine
the
circuit.
combinations
resistors
parallel
power
output
of
need
is
often
to
find
more
the
than
total
one
source
resistance
of
of
resistance
in
a
circuit
and
we
combinations.
combinations.
Resistors
The
R
R
1
R
2
3
total
their
=R
S
+R
1
would
+R
2
series
resistance
a
wire
expect
of
components
resistances.
with
the
5 Ω
This
is
resistance
complete
wire
in
series
exactly
to
to
a
is
as
wire
have
a
simply
you
the
would
with
6 Ω
resistance
sum
of
expect.
If
resistance
of
you
you
11 Ω
3
More
4.11.1
in
respective
connect
R
Figure
range
to:
There

a
components
Resistor

contain
OUTCOMES
of
At
circuits
analysis
Resistors
in
formally
this
is
written
as:
series
R
=
R
s
Resistors
Finding
R
in
the
+
R
1
+
R
2
+
…
3
parallel
total
resistance
of
resistors
in
parallel
is
a
little
more
1
complicated.
R
voltage
Using
acting
the
across
fact
that
them,
this
the
resistors
equation
all
can
have
be
the
same
derived:
2
1
1
1
1
R
=
3
+
R
R
P
1
1
=
R
Figure
1
+
R
P
4.11.2
+
…
R
2
3
1
Power
R
2
Resistors
and
resistance
3
in
parallel
To
find
find
the
the
the
power
power
electrical
the
The
the
a
each
car’s
What
1
element
with
the
R
a
total
120
=
a
the
car
The
it
of
resistors
resistors
is
usually
current
rear
of
and
1
15 Ω
window
120 Ω.
strips
+
120
8
of
1
120
=
and
resistance
+
P
However,
resistance
P
R
combination
individual
and
much
use
we
then
could
use
easier
these
two
the
to
find
values
to
1
battery.
1
=
a
output.
12 V
is
of
the
equation.
EXAMPLE
heating
strips
of
resistance
power
WORKED
output
output
power
equivalent
find
126
R
1
+
R
1
+
are
of
the
120
rear
heater
in
window
1
+
120
contains
connected
1
+
The
using
heater?
1
+
120
metallic
parallel.
1
+
120
eight
operates
1
+
120
120
b
What
Find
is
the
the
power
current
of
the
through
heater?
the
heating
element
using
the
total
resistance:
V
I
12 V
=
=
=
0.8 A
SUMMARY
R
Finally
find
the
power
of
the
heater:
1
Find
the
three
P
=
QUESTIONS
15 Ω
IV
=
0.8 A
×
12 V
=
resistance
resistor
of
the
arrangements
9.6 W
shown
in
Figure
4.11.4.
a
20 Ω
Analysing
circuits
20 Ω
Using
the
resistance
equations
we
can
analyse
complex
circuits.
20 Ω
This
b
worked
example
will
lead
you
through
one
of
these
analyses.
40 Ω
60 Ω
40 Ω
WORKED
EXAMPLE
60 Ω
2
c
Analyse
this
circuit,
shown
6.0 V
in
Figure
currents
4.11.3,
I
and
to
the
find
the
100 Ω
100 Ω
potential
1
differences
V
and
200 Ω
V
1
2
400 Ω
First
find
the
total
resistance
100 Ω
I
of
the
circuit.
This
finding
the
parallel
section
means
resistance
(R
of
1
the
Figure
4.11.4
).
40 Ω
P
2
Find
the
current
in
each
of
5 Ω
1
1
1
=
3
+
R
40
the
=
20
two
parallel
resistors
in
20 Ω
40
Worked
P
example
2.
V
2
V
40
R
1
=
=
13.3 Ω
P
3
The
total
Figure
resistance
(R
)
of
4.11.3
the
KEY
POINTS
T
circuit
is
given
by:
1
R
=
R
T
+
5 Ω
=
The
resistance
components
Now
of
18.3 Ω
P
find
I
,
the
total
current
from
the
battery,
using
the
the
and
the
total
series
is
battery
1
voltage
in
sum
of
the
individual
resistance:
resistances
V
6 V
R
=
R
s
I
=
=
=
+
1
R
+
…
2
0.33 A
1
R
18.3 Ω
2
T
We
can
find
V
because
we
know
the
current
through
the
resistor
The
resistance
components
of
in
parallel
is
2
and
its
resistance:
V
=
2
I
R
=
given
0.33 A
×
5 Ω
=
1.65 V
1
by
1
we
know
that
the
total
voltage
drop
around
the
circuit
R
1
be
6.0 V
and
so
the
voltage
V
can
be
+
R
P
must
equation
1
=
Finally
the
+
…
R
1
2
found:
1
3
V
=
6.0 V
–
1.65 V
=
could
resistors
power
output
combination
1
We
The
continue
using
their
to
find
of
a
4.35 V
the
resistances
current
and
through
the
voltage
each
of
across
the
parallel
them.
sum
the
of
the
of
resistors
power
individual
is
outputs
the
of
resistors.
127
Section
SECTION
1
A
plastic
they
to
4:
Practice
rod
both
have
a
4
is
Practice
exam
rubbed
become
positive
questions
with
charged.
a
dry
The
is
until
7
found
What
is
the
What
cell
are
and
the
a
charge
on
the
Describe,
how
the
in
terms
rod
between
a
primary
cell?
Why
must
and
of
particle
cloth
a
voltmeter
have
very
high
cloth?
resistance
b
differences
secondary
charge.
8
a
questions
1
cloth
rod
exam
have
movement,
low
while
an
ammeter
must
have
very
resistance?
become
9
A
filament
lamp
operates
with
a
potential
charged.
difference
2
Sometimes,
tumble
and
when
drier,
tiny
a
clothing
crackling
sparks
can
be
is
taken
sound
seen.
out
can
Why
be
of
a
lamp
heard
does
into
of
12.0 V
transforms
heat
and
across
4000 J
light
of
energy
its
terminals.
electrical
in
one
energy
minute.
this
a
What
is
the
power
rating
b
What
is
the
current
c
What
is
the
resistance
of
the
lamp?
happen?
3
Describe
how
principles
accurate
4
Copy
of
a
static
copies
and
electrical
photocopier
of
electricity
an
complete
circuit
uses
to
table
reproduce
showing
symbols.
Component
Symbol
Component
lamp
semiconductor
diode
battery
5
The
dome
charged
The
to
a
dome
earth
of
is
What
What
0.02
6
A
6.0 V
the
is
128
particles
generator
charge
discharged
average
by
of
is
0.01 C.
connecting
it
wire.
travel
current
discharge
in
the
wire
if
the
in
the
wire
process
takes
What
is
connected
to
a
resistor
of
5 Ω
much
resistor
b
total
discharge?
battery
How
Graaff
a
grounding
of
the
the
de
holds
second?
resistance
a
a
type
during
Van
it
then
with
during
b
a
until
is
in
charge
one
the
passes
though
the
minute?
power
output
of
in
the
lamp?
the
image.
this
the
The
resistor?
Symbol
of
the
lamp?
1
10
A
student
investigates
characteristics
of
data
are
gathered
Voltage/V
Draw
this
b
c
a
the
current–voltage
semiconductor
shown
in
the
diode.
The
table.
−0.3
−0.2
−0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0
0
0
0
0
0
0
0.01
0.1
0.2
0.3
Current/mA
a
a
diagram
of
a
circuit
suitable
for
13
investigation.
Plot
a
graph
Describe
the
of
Three
resistors
connected
the
results.
results
a
shown
in
the
Draw
Magnesium
chloride
dissolves
in
graph.
water
to
solution
containing
magnesium
(Mg
)
a
of
2.0 V
circuit
circuit
resistance
cell
in
diagram
of
the
with
a
showing
resistors
the
66 Ω
variety
be
ways.
the
when
highest
can
of
they
resistance.
form
b
2+
a
each
a
arrangement
form
11
a
to
Calculate
the
current
the
total
through
one
of
the
and
resistors.
chloride
(Cl
)
ions.
c
a
Describe
the
process
which
allows
Calculate
power
of
the
resistor
this
combination.
solution
to
conduct.
d
b
What
is
meant
by
an
ohmic
Repeat
with
c
Is
the
solution
an
ohmic
Calculate
the
resistance
of
the
b
and
lowest
c
for
the
configuration
resistance.
conductor?
14
12
a,
conductor?
these
three
Determine
the
readings
on
the
four
ammeters
resistor
and
two
voltmeters
in
this
circuit.
combinations:
a
8.0 V
50 Ω
20 Ω
40 Ω
b
40 Ω
A
A
1
4
40 Ω
66 Ω
A
10 Ω
2
c
66 Ω
A
40 Ω
3
33 Ω
33 Ω
V
1
V
2
33 Ω
129
4.12
Direct
current
alternating
Direct
LEARNING
the
end
of
this
topic
be
and
able
compare
direct
alternating
batteries
only
in
one
current
identify
(d.c.).
positive
to
This
is
a
negative)
current
and
has
that
a
magnitude.
peak
voltage
of
an
current
(a.c.)
is
used
in
mains
supplies.
The
direction
of
the
alternating
current
using
current
and
Alternating
current
current
(from
current
the
frequency
direct
and
Alternating

produce
direction
to:
fixed

current
you
travels
should
current
OUTCOMES
Cells
At
and
an
reverses
rapidly,
many
times
each
second,
and
the
magnitude
oscilloscope
varies.
trace

describe
the
cathode-ray
operation
of
a
Alternating
as
oscilloscope.
a
current
generator.
voltage
peak
varies
is
caused
These
will
be
sinusoidally
by
an
alternating
discussed
from
a
in
positive
voltage
4.23.
peak
The
source
such
magnitude
value
to
a
of
the
negative
value.
10
V /egatloV
ACTIVITY
In
the
Tesla
19th
and
century,
Thomas
8
Direct
current
6
4
Nikola
2
Edison
0
disagreed
about
use
or
whether
to
–2
–2
Time/10
direct
alternating
s
current
–4
for
mains
supplies.
Research
Alternating
–6
the
background
to
this
current
‘war
–8
of
the
currents’
and
find
out
–10
why
alternating
eventually
current
was
selected.
Figure
WORKED
EXAMPLE
is
alternating
a.c.
power
the
frequency
of
the
shown
in
Figure
1
=
the
From
period
the
of
in
Figure
diagram
one
to
The
peak
voltage
example
current
4.12.1
you
complete
can
is
for
a
measure
low
voltage
the
maximum
the
cycle.
oscillation.
this
is
is
the
highest
voltage
reached
over
In
±8.0 V
.
=
25 Hz

The
period
(T)
of
the
alternating
current
is
the
time
taken
for
one
0.04 s
complete
Finding
The
cycle.
the
This
In
the
example
is
of
the
a.c.
related
source
to
the
1
frequency
this
is
0.04 s.
frequency
frequency
second.
=
is
the
period
number
by:
1
or
f
=
period
T
−1
The
130
direct
1
=
T
supply.
and
shown
current
4.12.1?
the
f
voltage
alternating
a.c.

supply
Comparing
The
voltage
What
4.12.1
unit
of
frequency
is
s
or
hertz
(Hz)
of
complete
cycles
per
Exploring
In
3.12
sound
an
saw
electrical
The
two
volts
The

The
volts
per
time
when
and
analyse
also
be
be
sound
be
used
to
to
energy
displayed
used
time
of
when
an
the
voltage
investigate
was
on
converted
the
measure
to
oscilloscope
the
properties
base
if
is
alternating
control
alternating
the
oscilloscope
are
the
per
allows
you
source.
division
If
is
to
the
set
measure
wave
to
the
occupies
0.5 V/div
then
3.0 V
.
the
one
set
on
base:
volts
is
determines
example,
time
used
(volts/div)
voltage
base
an
then
controls
the
division
boxes
For
the
could
can
important
peak-to-peak
division.
To
which
could
The
currents.
division
vertical
the
oscilloscope
frequency.
oscilloscope
peak-to-peak
six
an
their
signal
most
per
that
and
alternating
The

you
waves
screen.
of
waveforms
time
represented
complete
to
0.2 s/div,
source
follow
wave
the
this
by
a
horizontal
occupies
period
is
four
divisions
0.8 s.
procedure:
Figure

Connect

Adjust
the

the
source
vertical
waveform
Adjust
the
the
the
period
can

Measure
and

Measure
the
the
volts
can
time
to
per
clearly
base
be
a.c.
so
input
division
be
seen
that
at
terminals
until
on
least
the
one
the
of
the
peak
current
the
period
source,
and
trough
of
screen.
full
wave
can
be
seen
and
peak
of
the
or
peak-to-peak
source
and
KEY
voltage.
calculate
the
can
also
which
be
would
used
be
to
measure
displayed
as
the
a
POINTS
frequency.
voltage
horizontal
of
a
Direct
one
direct
current
Alternating
direction
in
only
current
and
switches
magnitude.
oscilloscopes
3
Cathode-ray
oscilloscopes
are
expensive
and
can
be
difficult
Oscilloscopes
operate.
Most
waveform
analysis
is
now
carried
out
using
which
SUMMARY
Find
the
shown
be
connected
directly
to
a
be
used
properties
to
of
signals.
computer.
QUESTIONS
peak
in
can
the
digital
a.c.
oscilloscopes
can
to
investigate
1
travels
direction.
line.
2
Digital
oscilloscope
measured.
note
oscilloscope
An
oscilloscope.
1
The
4.12.2
voltage,
Figure
period
and
frequency
of
the
a.c.
4.12.3.
source
2
Sketch
of
the
appropriate
following
graphs
a.c.
waveforms:
20
a
an
a.c.
source
with
a
V / egatloV
15
peak
10
and
voltage
a
of
110 V
frequency
of
50 Hz
5
b
0
an
a.c.
peak
and
–5
source
voltage
a
with
of
a
20 mV
frequency
of
2 kHz.
–2
Time / 10
s
–10
–15
–20
Figure
4.12.3
131
4.13
Mains
the
Mains
LEARNING
the
end
of
this
topic
be
supply
electricity
able
and
describe
the
mains
in
the
describe
the
what
would
a
device
the
reasons
voltage
is
were
wrong
voltage
mean
supplied
vary
as
alternating
from
island
to
current.
island
The
in
mains
the
supply
Caribbean
for
(Figure
4.13.1).
varying
continuously
over
a
cycle
the
effective
is
used
square
to
(r.m.s.)
describe
voltage
the
as
mains
shown
supply.
in
T
able
This
is
called
the
4.13.1.
connected
Higher
to
is
frequency
happen
root
if
frequency
Caribbean
average

and
supply
As
used
voltage
to:
historical

Caribbean
you
voltage
should
in
OUTCOMES
Mains
At
electricity
type
of
voltage
supplies
can
provide
the
same
power
using
smaller
mains
currents
allowing
thinner
wires
to
be
used.
However,
higher
voltages
supply.
are
more
Mains
T
able
4.13.1
Mains
supply
in
supplies
spikes
Cuba
Voltage
Frequency
/V
/Hz
115
110
often
the
slightly
supply
picks
‘noisy’.
up
The
smooth
interference
from
curves
other
have
electrical
50
60
Some
equipment
can
be
sensitive
to
this
noise.
350
V /egatloV
Barbados
as
islands
devices.
Island
are
some
slight
Caribbean
dangerous.
St
Kitts
&
Nevis,
300
220 V
r.m.s.
250
Barbados,
200
115 V
Jamaica
110
or
50
220
St
Kitts
and
Nevis
110
or
r.m.s.
150
100
50
60
0
230
–50
St
Martin
120
or
50
–2
–100
Time/10
230
s
–150
Trinidad
115
50
–200
and
–250
Tobago
–300
–350
–400
Figure
Ring
An
the
wires
The

a
live
high
The
132
are
of
between
wire
called
domestic
used
current
neutral
Many
and
varies
islands
in
the
Caribbean
to
in
the
ring
several
(coloured
a
ring
power
main
devices
brown)
main
sockets
and
at
they
once
provides
is
used
(Figure
are
thick
without
the
as
the
4.13.2).
basis
T
wo
enough
for
or
to
overheating.
power
and
operates
at
voltage.
current

supply
configuration
connection
provide
a
Mains
mains
electrical
three

4.13.1
to
wire
flow
devices
yellow).
(coloured
in
are
a
closed
also
blue)
completes
the
circuit,
allowing
the
circuit.
connected
to
an
earth
wire
(coloured
green
L
10 A
or
15 A
E
socket
with
N
earth
N
E
L
2
wires
2.5 mm
In
a
ring
each
or
‘ring’,
and
the
2-pin
main
wire
circuit
forms
which
ends
at
a
the
consumer
loop,
fuse
4.13.2
A
ring
socket
earth
unit
10 A
main
with
in
Double
socket
Figure
Switched
begins
2-pin
socket
with
earthed
Figure
sockets
4.13.3
Make
your
sure
plugs
that
and
you
match
sockets
correctly.
Plugs
Some
and
sockets
electrical
mains
supply,
disconnected
plugs
and
(Figure

Type
Type
but
most
easily
sockets
such
are
and
used
as
ovens,
connected
moved.
and
In
these
the
are
are
by
wired
a
plug
directly
so
Caribbean
referred
to
that
there
as
into
they
are
type
A
the
can
two
and
be
main
type
B
4.13.3).
A
plugs
neutral

devices,
B
earth
have
only
two
pins
which
connect
to
the
live
and
wires.
plugs
have
three
pins.
The
additional
pin
is
connected
to
the
SUMMARY
1
The
different
plugs
are
matched
by
different
sockets
and
a
type
Why
should
not
be
inserted
into
a
type
B
shouldn’t
plug
type
to
the
wrong
there
are
accidently

several
connect
Connecting
to
take
a
a
different
a
device
110 V
large
device
current.
mains
to
the
to
This
a
voltages
wrong
220 V
will
most
in
use
it
is
possible
to

causing
Connecting
receiving
won’t

a
too
work
Connecting
220 V
low
at
a
severe
a
main
supply,
supply
likely
will
melt
cause
the
the
wires
to
current.
the
electrical
B
to
a
advantages
does
a
ring
provide?
the
POINTS
a
110 V
The
supply
device
will
will
not
result
in
operate
the
device
correctly
1
or
Mains
and
designed
reverse,
is
to
operate
also
likely
with
to
a
50 Hz
damage
supply
the
to
device
components
will
not
function
electricity
supplied
at
at
can
different
50 Hz
or
be
voltages
60 Hz.
a
Always
connect
a
device
to
as
the
its
type
damage.
device
device
a
device
in
all.
or
from
supply.
2
60 Hz
change
electrical
A?
What
KEY
device
an
supply
2
As
on
socket.
device
Connecting
you
A
the
plug
QUESTIONS
wire.
correct
type
of
supply
correctly.
using
the
correct
kind
of
plug.
133
4.14
Mains
Mains
LEARNING
the
end
should
be
of
this
able
topic
force
describe
and
you
of
to:
how
fuses
be
able
to
correct
fuse
for
a
enough
this,
and

is
dangerous
because
the
voltages
are
large
enough
OUTCOMES
to
At
electricity
safety
current
to
start
safety
the
through
electrical
features
your
fires
need
body.
if
to
The
there
be
is
currents
a
fault
in
incorporated
can
the
to
also
be
device.
protect
large
Because
the
device
user.
operate
identify
the
Fuses

state
a
the
circuit
explain
device
advantages
breaker
compared

a
to
the
a
If
of
circuits
when
fuse
function
there
of
is
fault
and
device
will
would
heat
in
an
connects
be
small
the
electrical
to
the
and
wires
a
in
device
neutral
large
the
where
wire
current
device
then
will
and
the
the
flow.
could
live
wire
short
resistance
This
cause
large
a
fire.
of
the
current
A
fuse
an
prevents
earth
a
this
by
being
the
‘weakest’
point
in
the
circuit
a
thin
piece
and
melting
wire.
before
held
any
other
inside
Fuses
a
need
operation
to
An
be
but
WORKED
part.
glass
or
selected
only
if
fuse
so
there
consists
that
is
of
of
wire,
often
tube.
an
they
will
excess
not
melt
in
normal
current.
EXAMPLE
air-conditioning
power
The
ceramic
rating
of
unit
1.0 kW.
is
designed
What
size
to
operate
fuse
should
at
220 V
be
used
with
with
a
this
unit?
First
find
the
normal
operating
P
Figure
4.14.1
Fuses
have
ratings,
5 A,
specific
such
as
P
current
1 A,
=
IV
so
I
current
=
=
=
V
3 A,
of
the
unit:
1000 W
4.55 A
220V
13 A.
Then
It
select
a
fuse
that
operating
current.
should
noted
device.
and
be
A
this
current
small
In
case,
fuses
only
increase
slightly
this
that
of
is
a
in
larger
a
5 A
alone
few
do
fuse
not
milliamps
current
than
would
is
the
normal
appropriate.
protect
is
the
enough
not
cause
to
a
operator
kill
fuse
a
to
of
a
human
melt.
Switch
(held
closed
by
spring)
Circuit
Circuit
the
breakers
excess
circuit.
having
A
residual
device.
Figure
4.14.2
A
circuit
breaker
uses
to
break
too
134
when
large.
the
faster
part
the
manner
magnetic
and
more
advantage
circuit
compares
similar
a
(Figure
breaker
current
of
fuses
and
sensitive
being
able
but
they
cutting
than
to
a
be
fuse.
reset
rely
off
on
the
Circuit
without
4.14.2).
(RCCB)
in
to
switch
the
is
live
an
even
wire
and
more
the
sensitive
neutral
current
should
be
exactly
the
same.
If
there
is
even
a
very
small
wire
current
the
leak
circuit
is
the
the
current
a
an
which
electromagnet
It
have
replace
in
opening
process
also
to
operate
current
This
breakers
Electromagnet
breakers
(through
the
user
is
the
current
is
cut
off.
of
a
device)
then
the
circuit
breaker
opens
and
The
An
earth
electrical
becomes
live
wire
wire
device
live
(is
breaks
Some
devices
made
from
becomes
connected
inside
the
dangerous
the
live
wire).
to
the
This
user
can
if
its
happen
case
if
the
device.
automatically
insulating
very
to
protect
materials
the
such
as
user
because
plastic.
Even
they
if
are
the
live
wire
Figure
becomes
feature
Figure
If
the
loose
are
it
cannot
double
electrocute
insulated
and
the
user.
should
Devices
carry
the
with
symbol
this
4.14.3
safety
shown
This
an
indicates
is
that
double
insulated.
in
4.14.3.
case
receive
a
is
metal
fatal
and
electric
is
in
contact
shock
on
with
touching
the
it.
live
A
wire,
fuse
a
alone
user
can
would
a
Safe
F use
not
symbol
appliance
prevent
touches
this,
the
as
no
additional
current
would
flow
until
the
Heating
element
user
device.
L
To
prevent
wire:
the
these
earth
accidents
wire.
This
the
wire
case
can
provides
be
a
connected
low
to
resistance
an
additional
route
for
N
the
current
the
user.
to
pass
to
earth
and
so
the
current
will
not
pass
through
Switch
Also,
the
large
current
will
cause
the
fuse
to
melt
or
circuit
E
breaker
to
trip,
breaking
the
circuit
(Figure
Metal
case
4.14.4).
Current
path
ACTIVITY
Inspect
the
plugs
and
electrical
information
on
a
range
of
b
Protected
Heating
the
electrical
devices
to
find
out
their
power
rating,
operating
element
metal
voltage
making
and
of
the
fuses
yourself
type
the
of
mains
devices
without
supply
need.
expert
they
Don’t
require.
try
to
Work
carry
out
out
any
touches
case,
which
it
live
type
rewiring
L
supervision!
N
SUMMARY
QUESTIONS
E
1
Why
should
2
What
you
use
the
correct
fuse
in
an
electrical
device?
Current
should
you
do
if
the
circuit
breaker
in
your
house
tripping?
Figure
4.14.4
The
user
3
What
T
able
fuses
do
the
Power
washing
1
machine
tumble
drier
electric
lamp
T
able
4.14.1
from
wire
protects
the
electrocution.
require?
rating/W
Mains
voltage/V
800
110
1200
230
80
120
POINTS
Fuses
live
2
in
earth
4.14.1
Device
KEY
devices
path
keeps
The
an
and
wire
circuit
breakers
becomes
earth
wire
electrical
too
break
large
protects
the
due
user
circuits
to
a
if
the
current
in
the
fault.
from
electrocution
in
case
of
fault.
135
4.15
Conversion
to
The
LEARNING
the
end
of
this
topic
be
d.c.
need
is
able
much
that
easier
explain
why
sometimes
a.c.
need
to
a
to
to
voltage
be
of
alternating
transmitted
current
efficiently
over
long
in
power
current
is
also
much
easier
to
produce
from
the
stations.
be
many
to
devices
work
an
alternating
properly.
current
However,
some
will
provide
devices,
the
energy
including
they
computers,
diagram
require
how
converted
the
can
d.c.
circuit
showing
increase
energy
Alternating
generators
sources
need
draw
current
to:
For
converted

direct
to
electrical
distances.

for
you
so
should
a.c.
OUTCOMES
It
At
of
a.c.
can
direct
current
at
very
steady
voltage
levels
to
operate
correctly.
be
d.c.
Rectification
The
process
called
shown
so
if
in
one
current
Figure
is
one
half
a.c.
of
diode
the
alternating
will
to
only
an
relies
allow
current
on
the
current
alternating
to
in
supply
a
direct
properties
one
there
current
of
diodes
direction
will
only
is
as
and
be
a
time.
rectification
from
shows
an
the
a
circuit
alternating
direction
represents
power
A
an
Rectification
connected
4.15.1
current
in
converting
4.10.
Half-wave
Diode
of
rectification.
and
so
the
resistance
of
which
supply.
output
the
can
The
be
current
device
used
diode
the
is
to
only
produce
allows
direct.
power
The
a
direct
current
load
supply
is
resistor
connected
to.
supply
To
Resistor
oscilloscope
Figure
4.15.1
Simple
If
we
an
can
see
The
current
that
half-wave
rectification
use
it
from
oscilloscope
what
is
happens
provided
only
in
maximum
all.
to
in
by
measure
the
half-wave
one
direction.
zero
current
at
This
current
required
is
by
very
rectification
However
value
and
inefficient
electronic
Improving
rectification
One
improve
voltage
across
the
load,
we
circuit.
to
a
the
for
the
direct
voltage
periods
and
is
does
of
not
is
in
still
time
the
varying
there
provide
sense
is
the
no
type
of
devices.
+
way
egatloV
4.15.2).
a
period
short
produces
a
A
of
the
profile
capacitor
time.
smoothed
is
a
Adding
d.c.
of
the
simple
it
on
output
to
as
current
device
the
is
to
simple
shown
use
which
by
a
capacitor
stores
charge
half-wave
the
blue
for
rectifier
line.
0
Time
When
the
charge
When
Figure
4.15.2
Smoothed
half-wave
rectification
plates
voltage
will
the
current
than
136
to
(Figure
in
is
rising
stored
voltage
the
and
the
be
is
load.
provide
current
on
and
the
decreasing
However
a
there
current.
provided
is
a
current
in
the
load
some
capacitor.
by
there
the
This
the
would
capacitor
current
a.c.
normally
will
will
source.
be
release
decrease
a
decreasing
charge
more
from
slowly
its
During
the
continue
If
the
sections
to
where
discharge
frequency
of
and
the
there
is
no
provide
source
a
were
voltage
the
capacitor
will
current.
low,
the
capacitor
would
+
discharge
has
to
almost
discharge
completely.
slightly
and
At
the
high
frequency,
current
the
provided
is
capacitor
only
therefore
fairly
egatloV
constant.
Full-wave
In
is
Time
rectification
half-wave
current
0
rectification
actually
complicated
you
producing
circuit
can
a
involving
see
useful
four
that
only
direct
diodes
half
of
current.
can
be
the
A
used
alternating
more
to
produce
Figure
a
positive
potential
producing
supplies
a
a
negative
much
SUMMARY
1
Sketch
difference
even
voltage.
steadier
d.c.
This
when
gives
supply
the
alternating
full-wave
(Figure
supply
rectification
4.15.3
which
4.15.3).
QUESTIONS
the
a.c.
full-wave
rectification
oscilloscope
trace
you
would
expect
to
see
when
EXAM
the
Smoothed
is
source
a
half-wave
b
full-wave
in
Figure
4.15.4
TIP
is:
rectified
Alth
ough
rectified.
have
to
you
know
capa
citor
s
fullwave
do
no t
how
wo rk
or
rectifi
catio
n
110
o pera
tes,
V / egatloV
a.c.
can
into
0
a
remem
ber
be
steady
contin
uous
0
0.01
0.02
0.03
and
d.c.
0.04
fairl
y
that
trans
fo rm
ed
supp
ly
easily
.
Time / s
–110
Figure
2
Redraw
been
KEY
1
4.15.4
the
traces
smoothed
as
by
they
a
would
appear
if
the
output
had
capacitor.
POINTS
Alternating
not
all,
current
electrical
can
provide
electrical
energy
for
most,
but
devices.
2
Rectification
is
used
3
Rectification
relies
to
on
convert
the
a.c.
into
properties
of
d.c.
diodes.
137
4.16
Logic
circuits
1
Binary
LEARNING
OUTCOMES
Computer
At
the
end
of
this
topic
binary
should
be
able
describe
are
how
binary
represented
in
numbers
computer
find
0
and
the
output
from
a
number
gate
unlike
are
4.16.1
using
digital
system
only
information
contains
two
represented
digits
as
a
represented
our
decimal
but
only
decimal
as
1s
system
a
string
and
0s
numbers
which
of
are
contain
digits
used.
just
T
able
represented
as
ten
as
in
digits.
any
4.16.1
four
other
shows
binary
digits.
simple
numbers
can
be
represented
physically
in
a
number
of
ways.
In
system.
Examples
numbers
four
Decimal
binary
represented
system
electronics
T
able
operate
The
example
Binary
logic
1
Numbers
some
systems

system.
to:
by

systems
you
of
binary
Binary
high

low
The
decimal
represented

as
which
which
exact
what
they
are
represents
represents
voltage
type
of
represented
the
the
levels
as
digit
digit
vary
is
1
0
from
semiconductor
two
voltage
and
and
is
is
system
being
levels:
called
called
to
logic
logic
system
1
0.
depending
on
used.
digits
Decimal
Binary
0
0000
6
0110
1
0001
7
0111
2
0010
8
1000
3
0011
9
1001
4
0100
10
1010
5
0101
11
1011
Logic
A
gates
logic
input
gate
and
is
an
electronic
produces
a
component
binary
output
which
based
on
processes
a
set
of
a
binary
rules.
Examples:

A
NOT
input.
1
gate
This
output
As
the
An
is

The
AND
Y
ou
of
a
are
to
expect
ed
find
logic
the
gate
to
a
in
three
any
the
the
there
logic
is
1
opposite
a
logic
input
of
0
the
input
there
the
same
is
input
as
there
a
is
logic
these
the
a
0
logic
output.
gates
are
a
logic
1
output
if
one
or
other
of
its
inputs
gate
produces
are
list
both
of
the
a
logic
logic
five
1
output
if
its
first
input
and
its
1.
gates
.
logic
gates
you
are
required
to
know
is
you
4.16.1.
Truth
tables
system
tables
show
the
output
the
gate.
states
of
a
logic
gate
for
all
of
the
maxim
um
T
his
can
combi
natio
n
three
Figure
be
output
possible
be
a
not
inverters.
produces
input
complete
Truth
contai
ning
of
is
is
TIP
shown
able
when
which
1.
second
EXAM
output
there
always
called
gate
logic
is
an
that
when
output
OR
An
means
but
sometimes

produces
see
on
of
these
the
inputs
output
When
in
consult
doubt
the
to
would
be
about
truth
These
when
the
what
table.
For
a
allow
gates
logic
us
are
gates
example
the
to
easily
determine
connected
does,
truth
you
table
to
input
should
shows
what
sources.
always
that
an
OR
page
s.
gate
logic
138
will
1.
still
produce
a
logic
1
output
even
if
both
of
the
inputs
are
Symbol
Gate
low
voltage
voltage
OUTPUT
A
Truth
Function
(high
=
=
=
0)
WORKED
table
INPUTS
1,
A
B
0
0
0
0
1
1
1
0
1
1
1
1
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
What
system
if
B
A
OR
B
=
OUTPUT
A
are
required
the
for
input
the
conditions
logic
gate
1
OUTPUT
OR
EXAMPLE
OUTPUT
1
=
to
shown
produce
in
an
Figure
output
4.16.2
of
0?
A
1
OUTPUT
if
AND
B
A
AND
B
=
1
Output
B
OUTPUT
OUTPUT
A
=
C
0
0
1
0
1
0
0
1
1
0
0
0
1
0
1
1
1
0
1
1
1
0
if
NOR
B
A
OR
B
=
OUTPUT
Figure
1
=
4.16.2
Draw
up
the
truth
table
for
the
0
OUTPUT
A
logic
if
NAND
B
A
AND
B
=
1
a
sensible
sure
OUTPUT
OUTPUT
if
INPUT
=
1
=
0
0
1
1
0
gate
all
of
system
order
the
combinations
working
and
making
possible
are
in
input
covered
NOT
OUTPUT
=
0
=
1
(T
able
4.16.1).
INPUT
if
INPUT
T
able
Figure
4.16.1
Combining
Logic
gates
together
to
be
To
work
table
of
all
have
they
and
can
their
truth
4.16.1
tables
Input
Input
Input
out
the
in
be
use
used
output
turn
output.
the
all
of
work
Keep
possible
A
B
C
individually
to
process
but
when
information
they
and
are
0
0
0
1
1
0
0
0
0
1
0
1
1
1
0
1
0
0
1
1
1
0
1
1
0
1
1
1
1
1
1
1
combined
cause
actions
for
the
your
on
input
any
collection
possible
way
going
of
input
through
until
you
gates
draw
up
combinations.
the
logic
have
a
truth
For
each
combinations
found
the
set
and
outputs
for
combinations.
From
SUMMARY
that
gate
Draw
up
the
a
truth
table
for
the
logic
gate
systems
shown
4.16.3
and
the
table
we
output
of
is
0
system
can
logic
the
logic
only
in
when
Figures
truth
QUESTIONS
see
1
Output
gates
limited
representing
the
of
logic
gates
taken.
inputs
find
Logic
A
is
1,
B
is
0
and
C
is
0.
4.16.4.
a
b
A
KEY
POINTS
A
1
Binary
digits
can
be
Output
B
B
Output
represented
by
high
and
low
C
voltage
Figure
4.16.3
Figure
2
Logic
gates
inputs
2
Design
a
logic
gate
system
to
match
levels.
4.16.4
the
and
process
produce
binary
binary
following:
outputs.
a
Three
inputs
when
any
Three
inputs
A,
one
B
of
and
the
C
which
inputs
is
produce
an
output
of
1
3
1.
Simple
be
b
D,
E
and
F
which
produce
an
output
of
logic
combined
all
of
the
inputs
are
to
can
provide
1
additional
when
gates
processing.
0.
139
4.17
Logic
Logic
LEARNING
gates
are
the
end
should
be
of
this
able
topic
you
are
then
devices
to:
output

find
the
output
combined
from
combination
to
of
conditions
processed
are
and
through
triggered.
device
with
digital
The
activates
a
produce
sensors
sequence
logic
only
logical
which
gates
when
of
are
the
signals.
logic
are
logic
gates
designed
required
and
so
that
simple
produce
Logic
gates
when
logic
the
gates
desired
sensors
are
devices
triggered
level
outputs
are
process
circuits
by
results
signals
of
produce
input
met.
gates
logic
involving
the
environmental
Output
design
signals
output
sensors
Sensors

detect
These
a
conditions
attached
often
2
OUTCOMES
environmental
At
circuits
processing
which
output
activated.
Sensors
The
sensors
symbols
as
produced
T
able
connected
shown
by
in
these
to
the
T
able
sensors
logic
4.17.1.
in
system
The
different
can
table
be
also
represented
shows
environmental
the
by
outputs
conditions.
4.17.1
Sensor
Symbol
Produces
switch
logic
0
Produces
when
when
open
closed
logic
1
S
temperature
temperature
is
low
temperature
is
high
T
light
in
darkness
in
light
L
pressure
not
under
pressure
under
pressure
P
Figure
4.17.1
A
data
logging
connected
to
a
device
computer
In
reality
these
thermistors
supplies.
output

A
0
sensors
light
point
to
a
temperature
the
pressure
is
applied
other
infra-red
are
at
which
logical
could
it
can
such
sensors
sensors,
be
1
level
as
mechanical
(LDRs)
be
from
finely
to
switches,
connected
switches
can
designed
a
to
voltage
logical
tuned.
switch
from
0
to
1
40 °C.
output
somebody
possible
sound
sensor
of
above
switch
as
are
rises
such
resistors
the
output
sensor
sensor
to
devices
dependent
temperature
A
Many
140
The
of
when

or
from
0
stepping
such
sensors
as
tilt
and
to
on
1
a
when
switches,
even
a
large
force
mat.
pH
sensors,
radioactivity
sensors.
WORKED
An
alarm
and
a
The
alarm
will
check
open
the
must
check
NOT
if
gate
is
is
if
the
dark,
a
dark
a
is
dark
gate
of
its
door
be
light
it
only
system
be
inputs
and
inverted
when
be
using
are
a
door
logic
is
the
a
is
dark
is
required
switch
thus
it
implemented?
and
will
mechanical
the
to
this
AND
both
AND
so
triggered
when
open,
0
be
could
an
when
needs
into
the
that
logic
input
it
in
a
to
How
triggered
door
goes
zero
be
alarm
the
this
need
indicates
the
if
input
may
opened.
produce
so
logic
is
This
trigger
would
To
signal
door
opened.
To
EXAMPLE
and
1.
needed.
switch
NOT
this
This
were
gate
before
gate.
sensor
this
is
input
needed.
needs
to
This
be
produces
inverted
a
with
a
too.
S
Output
L
ACTIVITY
Complete
Figure
devices
This
gives
would
This
on
a
a
survey
of
the
4.17.2
be
the
logic
logic
could
be
1
circuit
only
shown
when
connected
to
the
an
in
Figure
door
alarm
is
4.17.2.
opened
system
or
The
and
be
it
rely
output
is
used
a
dark.
to
on
short
would
switch
you
use
every
electronics
report
be
day
and
about
different
that
write
how
life
without
this
technology.
light.
Computers
Digital
They
computers
process
‘clock’
which
electronics
contain
binary
stops
and
millions
operations
the
signals
at
of
logic
very
getting
microelectronics
have
gates
high
a
integrated
speeds,
mixed
had
in
up.
controlled
The
massive
circuits.
by
a
developments
impact
on
in
society
SUMMARY
over
the
phones
past
fifty
around
years.
the
For
world
example,
are
linked
computer
together
systems
through
and
the
internet
1
providing
almost
instant
access
to
information
for
billions
of
A
bank
POINTS
alarm
Digital
can
be
designed
to
produce
logic
level
when
somebody
or
floor
on
environmental
Logic
the
circuits
required
can
process
signals
from
sensors
and
to
produce
Computer
undertake
only
the
sound
vault.
happen
is
steps
on
This
when
the
has
been
Design
primed
accomplish
a
logic
by
a
this
system
task.
outputs.
2
3
of
a
conditions.
switch.
2
have
signals
alarm
depending
to
which
heard
the
sensors
needs
system
activates
should
1
vault
people.
an
KEY
QUESTIONS
mobile
systems
very
contain
complex
millions
of
processing.
logic
gates
to
Design
could
a
logic
activate
raining
at
circuit
an
which
alarm
if
it
is
night.
141
Section
SECTION
1
Describe
current
2
4:
An
Practice
the
and
time
supply
base
Practice
exam
differences
direct
oscilloscope
power
4
has
is
questions
between
exam
used
to
alternating
7
been
set
to
analyse
an
trace
0.05 s
a.c.
8
shown.
per
The
the
volts/div
has
been
set
to
is
the
function
of
a
fuse
and
how
does
operate?
What
are
when
compared
the
advantages
to
a
of
a
circuit
breaker
fuse?
division
9
and
What
it
the
2
2
current.
producing
questions
Draw
a
circuit
diagram
showing
how
an
2 V/div.
alternating
to
current
produce
a
rectification
10
Sketch
a
a
b
an
a
direct
system
d.c.
source
a.c.
source
and
half-wave
period
of
of
be
be
How
voltage
with
rectified
can
this
improved?
graphs
peak
a
showing:
10 V
period
voltage
rectified
0.2
half-wave
current.
voltage–time
seconds
c
can
a.c
seconds
of
of
0.2
8 V
source
and
with
peak
a
voltage
of
8 V
d
a
What
is
the
peak
voltage
of
the
a
half-wave
rectified
a.c
source
with
a
power
period
of
0.2
seconds
and
peak
voltage
supply?
of
b
What
is
the
period
of
the
c
What
is
the
frequency
power
8 V
large
of
the
a.c.
Explain
sockets
why
in
a
ring
main
circuit
is
used
for
wall
Copy
Select
output
smoothed
using
a
capacitor.
and
complete
describing
their
this
table
of
logic
gates
functions.
houses.
Logic
4
the
source?
11
3
with
supply?
the
appropriate
fuse
for
each
of
Symbol
Description
the
gate
following
and
devices
from
the
range
1 A,
3 A,
5 A
Inverts
12 A.
the
symbol
Device
Operating
logic
Power
vice
voltage/V
filament
lamp
110
80 W
110
500 W
AND
air-
Produces
and
conditioning
to
logic
a
1
and
versa)
logic
portable
0
input
(changes
1
an
output
when
input
B
input
are
logic
220
electric
drill
220
electric
grill
110
1
2 kW
300 W
1.5 kW
NAND
5
How
does
faulty
an
earth
electrical
wire
protect
the
user
of
a
device?
NOR
6
Explain
why
the
core
of
an
electrical
cable
Produces
from
copper
but
the
outer
sheathing
142
from
flexible
plastic.
1
when
both
is
inputs
made
logic
is
output
made
a
are
logic
A
both
unit
kettle
of
0
12
Copy
the
and
complete
possible
logic
inputs
this
for
truth
this
table
for
all
arrangement
of
13
of
How
can
NOR
gate
an
AND
and
gate
two
be
NOT
constructed
from
a
gates?
gates.
14
Design
only
the
logic
sounds
circuit
during
for
an
daylight
alarm
and
which
when
it
is
A
raining.
B
Y
C
D
Input
A
Input
B
Input
C
Input
0
0
0
0
1
0
0
0
0
1
0
0
1
1
0
0
0
0
1
0
1
0
1
0
0
1
1
0
1
1
1
0
0
0
0
1
1
0
0
1
0
1
0
1
1
1
0
1
0
0
1
1
1
0
1
1
0
1
1
1
1
1
1
1
D
Output
Y
143
4.18
Permanent
Magnetic
LEARNING
the
end
should

be
of
this
able
describe
the
topic
Only
you
to:
effect
a
on
other
magnetic
describe
a
can
be
materials
magnadur.
be
metals
(unless
All
magnets
have
seeking)
when
placed
these
as
steel,
will
is
a
poles
south
poles
Opposite

Like
near
a
magnet.
not
magnetic
include
that
iron,
contain
attract
materials.
nickel,
these
cobalt
metals
non-magnetic
may
materials,
current
in
them
as
we
will
see
later).
which
(or
are
south
referred
seeking)
to
as
poles.
the
In
a
north
simple
(or
bar
are
at
either
end
but
magnets
can
be
made
in
The
Magnetic
of
magnets
coloured:
and
blue
red
for
are
attracted
the
between
attract
repel
poles
closer
so
poles
may
be
found
in
other
locations.
interactions
poles
poles
between
poles
and
interactions


north
there
two
and
shapes
north
often
such
These
same
made.
The
The
magnetic.
these
permanent
Magnetic
4.18.1
are
Magnets
from
and
several
Figure
made
Alloys,
magnetic.
magnet
magnet
forces
are
magnets
magnets
materials
how
few
also
north

themselves
and
even
have
experience
OUTCOMES
Magnets
At
materials
magnets
each
repel
the
the
magnets
each
other:
north
magnets
can
other:
south
be
summarised
south
poles
poles
repel
by
attract
south
these
north
poles,
rules:
poles.
and
poles.
are
to
each
other,
the
stronger
the
force
magnets.
materials
towards
placed
near
either
pole
of
a
magnet
bar
magnet
will
be
it.
for
south.
Magnetic
When
an
induction
iron
nail
is
placed
on
the
end
of
a
it
can
be
ACTIVITY
used
to
attract
induced
Suspend
a
magnet
as
shown
4.18.2
and
use
a
the
iron
iron
nail.
nails.
The
We
nail
say
is
that
magnetism
temporarily
acting
has
as
a
been
magnet
in
but
Figure
in
other
will
stop
acting
this
way
when
it
is
removed
from
the
permanent
second
magnet.
magnet
identify
prove
with
its
that
between
the
the
the
closer
known
poles.
polarity
Can
size
you
of
the
magnets
they
are
to
also
If
force
increases
we
try
magnet
has
been
Iron
process
also
removed
and
used
do
S
Iron
same
may
with
retain
from
the
a
steel
some
of
nail
its
permanent
the
nail
magnetic
will
act
as
properties
a
after
it
magnet.
together?

Force
the
but
N
of

to
not
Steel
is
mumetal
make
retain
classed
magnetism
classed
magnetise
bar
are
temporary
but
as
it
a
hard
will
as
soft
magnets.
magnetic
They
are
easy
materials
to
and
magnetise
are
but
well.
magnetic
retain
its
material.
magnetism
for
It
is
more
longer.
It
difficult
is
used
to
to
attraction
make
Figure
4.18.2
Testing
the
between
144
forces
magnets
permanent
magnets.
Magnadur
magnets
are
also
permanent.
Making
A
a
new
magnets
permanent
permanent
permanent
magnet
magnet
magnet
can
along
must
its
only
...and
be
made
length
be
as
from
moved
repeat
many
a
shown
in
one
steel
in
bar
by
Figure
rubbing
4.18.3.
The
direction.
times
ACTIVITY
Make
your
using
the
Figure
be
for
Figure
4.18.3
Making
Breaking
magnets
A
will
magnet
dropping
a
lose
a
permanent
some
permanent
of
its
Can
stronger
longer
shown
the
if
it
in
magnet
is
rubbed
time?
magnet
strength
magnet
magnet
technique
4.18.3.
made
a
own
onto
if
the
it
is
struck.
floor
will
Repeatedly
weaken
EXAM
its
TIP
magnetism.
Only
a
few
mag
ne tic
.
the
SUMMARY
QUESTIONS
all
1
Copy
and
between
T
able
complete
the
to
North
north
Why
bar
KEY
1
is
to
south
steel
two
showing
the
me ta
ls
of
mak
e
thinki
ng
are.
interactions
magnets.
rather
South
to
south
than
iron
South
to
north
used
to
make
small
permanent
magnets?
POINTS
Magnets
produce
magnetic
2
of
4.18.1
mista
ke
are
4.18.1
North
2
poles
T
able
materi
als
Don’
t
Permanent
as
forces
which
act
on
other
magnets
or
materials.
magnets
are
made
from
magnetic
materials
such
steel.
3
Like
4
The
poles
size
distance
repel
of
the
and
force
unlike
poles
between
attract.
magnets
decreases
with
their
apart.
145
4.19
Magnetic
Magnetic
LEARNING
the
end
of
this
topic
be
able
have
already
produced
draw
and
plot
the
around
a
bar
are
describe
the
magnetic
magnetic
by
the
explain
how
a
shape
The
an
as
of
the
of
Iron
objects
between
by
magnetic
fields.
is
a
region
of
space
in
which
a
magnetic
material
will
magnetic
field
is
not
as
simple
as
that
of
an
electric
are
always
two
poles
involved.
magnetic
bar
represented
north
the
lines
as
pole
point
south
pole
a
series
would
away
of
be
which
pushed
from
(Figure
lines
the
by
show
the
north
the
field.
pole
of
direction
This
the
means
magnet
and
4.19.1).
magnet
field
the
shape
two
of
a
common
magnetic
ways
of
field
finding
the
shape
of
a
magnetic
field
magnets.
filings
filings
align
with
can
the
be
sprinkled
field
lines
around
and
the
the
shape
magnet.
of
the
These
fi eld
filings
will
be
will
seen
clearly
around
(Figure
shape
To
A
A
4.19.2).
of
the
prevent
placed
the
plotting
plotting
the
The
will
field
technique
when
filings
a
piece
more
sticking
of
is
particularly
than
to
paper
one
the
or
useful
magnet
magnet
wrapped
is
the
in
for
looking
at
the
involved.
magnet
plastic
can
be
film.
compass
compass
The
line
can
needle
and
compass
curve
This
field
under
magnet.
is
back
a
of
dot
moved
to
the
be
the
placed
against
compass
can
be
placed
repeatedly
south
will
pole
where
until
of
the
the
north
point
a
the
trail
pole
along
of
the
of
compass
dots
magnet.
The
is
a
bar
direction
is
pointing.
formed.
dots
of
can
This
be
4.19.2
joined
with
starting
the
The
is
is
Earth
to
curve
several
to
form
different
a
field
points
line.
near
The
the
whole
poles
process
until
the
is
repeated
shape
of
revealed.
magnetic
produces
the
whole
south
a
Earth’s
due
the
at
field
The
a
rotation
planet
pole
geographic
146
a
field
are
around
S
Iron
Figure
charged
acting
force
There
N
a
forces
force.
imaginary
Finding
The
field
a
is
towards
Lines
caused
there
field
that
4.19.1
between
the
compass
works.
Figure
acting
Earth
field

forces
Similarly,
field
The
produced
the
fields.
magnet
experience

that
electric
magnetic
A
field
by
to:
magnets

seen
you
are
should
fields
OUTCOMES
You
At
fields
of
this
north
as
if
field
magnetic
of
its
there
imaginary
pole.
field
metallic
were
bar
a
around
core.
bar
itself
The
magnet
magnet
lies
(Figure
magnetic
within
near,
but
4.19.4).
field
the
not
This
envelops
Earth.
at,
the
The
The
Earth’s
magnetic
field
has
been
used
for
navigation
for
ACTIVITY
thousands
thin
will
slice
of
of
align
years.
Lodestone
lodestone
itself
to
the
can
be
Earth’s
is
a
naturally
made
to
float
magnetic
magnetic
material
on
The
water.
and
a
lodestone
field.
Use
on
the
shapes
Magnetised
steel
pins
are
used
in
compasses
and
follow
the
techniques
page
146
of
the
but
these
are
suspended
inside
a
case
so
that
they
freely.
The
‘north
seeking’
pole
will
point
towards
the
of
the
Earth
because
it
is
attracted
to
the
as
it
magnetic
fields
two
permanent
arranged
as
shown
in
north
Figure
pole
the
magnetic
may
magnets
rotate
described
find
same
surrounding
principle
to
south
4.19.3.
pole.
a
The
Earth’s
from
the
harmful
magnetic
Sun
and
field
is
protects
also
the
useful
Earth’s
defl ects
surface
from
charged
particles
potentially
S
N
S
N
N
N
S
effects.
b
Magnetic
Axis
of
rotation
S
axis
~1
1°
c
S
N
S
N
d
S
N
N
Figure
Figure
4.19.4
The
Earth’s
magnetic
field
4.19.3
EXAM
When
SUMMARY
S
TIP
draw
ing
field
lines
remem
ber
1
How
can
iron
filings
be
used
to
reveal
the
shape
of
of
fields?
go
An
iron
nail
whether
is
this
seen
to
proves
attract
that
the
a
paper
bar
is
a
clip.
Comment
into
they
no rth
the
po le
south
come
and
po le.
on
T
he
magnet.
the
a
KEY
the
alwa
ys
that
magnetic
out
2
mag
ne tic
QUESTIONS
term
ino log
y
Earth
’s
bit
sure
POINTS
po les
confus
ing.
you
abou
t
can
be
Mak
e
unde
rstand
it
clear
ly.
1
Magnets
have
magnetic
2
The
magnetic
fields
around
them
which
affect
materials.
shape
of
the
fields
can
be
found
with
a
compass
or
iron
filings.
ACTIVITY
3
Field
lines
come
out
of
the
north
pole
and
enter
the
south
Find
out
about
the
aurora
pole.
borealis
4
The
and
Earth
has
protects
a
us
magnetic
from
field
some
which
cosmic
assists
rays.
with
navigation
and
and
what
aurora
causes
australis
these
phenomena.
147
4.20
Electromagnetism
Currents
LEARNING
The
At
the
end
of
this
topic
be
charges
able
sketch
the
magnetic
a
shape
field
of
the
formed
current-carrying
until
around
wire
and
apply
to
This
right-hand
the
grip
rule
direction
of
field
state
a
was
first
compass
there
point
in
a
To
was
a
demonstrate
filings
with
some
in
a
wire
produce
demonstrated
uses
of
near
a
wire.
current
different
Demonstrating
determine
the

the
moving
a
magnetic
field
around
the
by
in
The
Hans
Christian
the
compass
wire.
This
would
Ørsted
caused
point
when
he
the
northwards
compass
to
direction.
a
solenoid

fields
to:
placed

magnetic
you
wire.
should
and
OUTCOMES
or
bar
the
the
plotting
shape
shape
of
of
the
the
compasses
in
field
magnetic
a
similar
field
way
to
we
can
the
use
iron
techniques
used
magnets.
electroThe
current-carrying
wire
is
made
to
pass
perpendicularly
through
a
magnets.
sheet
is
of
horizontal
placed
show
be
on
that
the
there
sprinkled
confirming
card
is
onto
the
card
a
(Figure
and
the
circular
the
card
shape
of
4.20.1).
current
field
and
the
is
A
of
turned
around
these
set
will
the
plotting
on.
wire.
form
a
The
Iron
compasses
compasses
fi lings
pattern
of
can
will
also
circles
field.
Card
Field
Figure
To
determine
hand
Figure
4.20.2
Using
your
imagine
fingers
while
out
the
The
right
curling
around
sticking
in
the
the
your
thumb
of
current.
direction
fingers
The
of
magnetic
wire
field
148
way
shows
loops.
the
as
way
shown
the
in
of
Ørsted’s
field
lines
Figure
experiment
loop
you
can
use
the
‘right-
4.20.2.
called
solenoid
is
field
around
solenoids
similar
in
a
are
shape
single
used.
to
wire
The
that
of
is
not
strong
magnetic
a
bar
field
magnet
and
so
coils
outside
but
there
the
is
a
field
of
the
coil
too.
This
internal
field
is
almost
uniform.
The
fi eld
lines
you
are
which
which
rule’
version
Solenoids
inside
your
updated
wire
direction
curved
grip
An
hand,
your
conventional
4.20.1
all
parallel
to
each
other.
One
end
of
the
coil
acts
magnetic
and
the
other
acts
as
a
south
pole
(Figure
4.20.3).
as
a
north
pole
Increasing
The
the
strength

using

increasing

placing
of
more
strength
the
field
loops
of
the
magnetic
produced
(turns)
of
by
a
field
solenoid
is
increased
by:
wire
Field
the
an
current
iron
concentrating
core
the
in
the
inside
field
(north)
wire
the
lines
solenoid
creating
a
(this
has
strong
the
fi eld
effect
at
the
of
end
of
the
Current
core).
Powerful
electromagnets
can
be
produced
by
using
all
of
these
Figure
4.20.3
measures.
To
find
field
of
the
use
your
own
electromagnet
using
a
large
iron
nail,
a
power
supply
and
a
length
of
insulated
wire.
Wrap
around
the
nail
in
a
tight
coil
and
test
the
power
of
Be
careful
not
to
use
large
currents.
You
again.
fingers
of
the
around
in
the
thumb
will
direction
your
of
electromagnet.
can
direction
Your
the
the
point
wire
we
hand
curving
coil.
of
direction
your
the
current
low-
the
voltage
right
time
follow
Build
direction
the
current,
our
This
ACTIVITY
the
from
can
the
magnetic
field
add
(northwards).
a
variable
Using
resistor
their
They
are
medical

control
the
current.
electromagnets
Electromagnets
and
to
Scrap
can
strength
used
for
be
can
a
very
be
wide
useful.
They
controlled
range
of
by
can
be
turned
adjusting
applications
the
from
on
and
current
heavy
off
in
them.
industry
to
diagnosis.
yards
objects.
use
powerful
T
urning
off
the
electromagnets
electromagnet
to
lift
allows
up
cars
them
to
and
be
other
put
down
again.

An
electromagnetic
remotely.
the
A
small,
current
where
large
a
small
current
the
a
can
from
starter
fields
are
be
current
switch.
Examples
current
to
safe,
pulls
circuit.
Electromagnetic
in
and
electromagnet
high
relay
of
the
used
to
enters
The
operate
the
switch
these
relays
ignition
switch
electromagnet
is
actually
can
circuit
a
is
be
part
found
used
to
and
of
in
turn
a
cars
on
Figure
4.20.4
A
very
electro-
motor.
also
vital
in
electric
motors
as
you
will
see
SUMMARY
4.23.
1
What
QUESTIONS
advantages
electromagnets
KEY
strong
magnet
a
do
have
when
POINTS
compared
to
permanent
magnets?
1
A
current
plane
at
in
a
right
wire
produces
angles
to
the
a
circular
magnetic
field
in
a
wire.
2
Imagine
there
was
current-carrying
2
A
solenoid
is
a
coil
of
wire
which
produces
a
magnetic
field
coming
similar
to
that
of
a
bar
The
strength
of
the
magnetic
field
of
a
solenoid
is
using
more
loops
of
wire,
increasing
the
Sketch
current
an
iron
out
of
this
magnetic
pattern
around
this
and
imaginary
adding
the
increased
field
by
vertically
magnet.
book.
3
a
wire
wire.
The
current
is
core.
flowing
upwards.
149
4.21
Forces
from
magnetic
fields
When
LEARNING
a
wire
surrounding
At
the
end
should
be
of
this
able
topic
from
you
with
to:
a
describe
field
the
has
on
effect
a
a
the
a
current
wire.
permanent
each
magnet.

carries
there
will
be
a
magnetic
field
OUTCOMES
other.
This
is
If
the
magnet
A
force
the
wire
then
will
motor
is
placed
the
act
on
two
the
inside
the
magnetic
wire
and
magnetic
fields
the
will
field
interact
permanent
effect
magnetic
current-carrying
Demonstrating
the
motor
effect
wire

sketch
the
resultant
surrounding
carrying
two

use
a
wire
permanent
find
the
left-hand
direction
acting
on
Figure

The
magnets
be
demonstrated
simply
using
the
apparatus
4.21.1.

T
wo
produce
an
almost
uniform
magnetic
field
between
them.
of
a
thick
wires
hold
another
loose
wire,
so
that
a
complete
circuit
rule
made.
the
When
the
circuit
is
switched
on
the
current
in
the
loose
wire
will
current-
produce
carrying
can
magnets

force
in
effect
between
is
to
motor
shown
current-
placed
Fleming’s
The
field
a
magnetic
field
which
will
interact
with
the
field
from
the
wire.
permanent

The
If
the
loose
magnets.
wire
direction
reversed
then
will
of
the
experience
the
current
loose
wire
a
or
force
the
will
making
direction
move
to
the
it
of
jump
the
to
the
right.
magnetic
field
is
left.
S-pole
Plastic
ACTIVITY
If
you
have
shown
motor
in
the
copper
brass
wires
or
or
support
a
wooden
held
in
stand
apparatus,
Figure
effect
Thick
4.21.1,
using
the
test
the
method
described.
Iron
yoke
Magnadur
(unlike
Figure
The
The

4.21.1
size
size
The
of
of
the

The
current
The
be
150
in
strength
of
of
greater
acting
wire.
around
field
field
length
a
the
field
the
motor
V,
high
I,
d.c.
supply
effect
force
force
magnetic
stronger

the
Low
facing)
Demonstrating
the
magnetic
magnets
poles
will
the
wire
larger
will
the
and
a
the
wire
field
the
following:
stronger
the
the
interaction
with
magnets.
the
permanent
magnets.
A
force.
permanent
is
on
the
greater
from
greater
depend
current
the
permanent
magnetic
inside
if
the
wire
the
produce
wire
force
The
the
from
the
on
longer.
magnetic
field.
There
will
Fleming’s
left-hand
rule
EXAM
It
can
wire
be
in
motor
when
a
difficult
magnetic
rule)
we
Using
to
lets
know
your
left
work
field.
us
find
the
out
the
direction
Fleming’s
the
left-hand
direction
direction
of
of
the
of
the
the
rule
(also
force
current
and
force
acting
known
acting
the
on
on
as
the
magnetic
the
When
wire
in
field.
Separate
feel
thumb,
first
and
second
fi ngers
so
that
they
all
silly
to
right
angles
to
each
other
(see
Figure
Point
pole

your
to
Point
your
positive
your
First
south
finger
the
direction
terminal
finger
to
about

angles
Your
thuMb
(or
you
of
of
the
magnetic
Field
find
does
the
movem
ent.
4.21.2).
wo rk
It
.
(north
the
to
do
in
the
direction
negative
this
but
of
terminal).
always
the
You
keep
Current
may
the
(from
have
three
to
the
twist
fingers
at
First
right
lef t-h
and
help
pole).
seCond
hand
in
don’
t
usin
g
point
really

sitting
hall,
abou
t
direc
tion
at
are
exam
Flem
ing’s
hand:
your
you
the
rule

TIP
a
to
each
will
finger
=
Field
other.
show
the
direction
of
the
force
acting
on
the
wire
Movement).
Left
hand
SeCond
=
Understanding
The
force
magnetic
field
on
the
fields
(Figure
the
wire
so
it
field
arises
is
finger
Current
because
important
to
of
the
know
interaction
the
shape
of
of
the
the
two
resultant
ThuMb
=
Movement
4.21.3).
Figure
4.21.2
Fleming’s
SUMMARY
1
How
a
The
rule
QUESTIONS
the
force
current-carrying
acting
wire
in
on
a
field
between
two
can
left-hand
magnetic
the
field
be
increased?
permanent
magnets
almost
2
is
uniform
Figure
4.21.4
carrying
field
In
is
acting
which
acting
A
into
the
field
a
current-
magnetic
the
direction
on
Magnetic
shows
wire.
is
paper
.
the
force
wire?
into
the
paper
Current
Neutral
Flat
magnets
point
Figure
4.21.4
alone
The
fields
combine
Direction
like
KEY
this
of
1
The
field
POINTS
force
A
current-carrying
placed
by
the
wire
is
magnetic
2
wire
4.21.3
alone
Interaction
The
direction
acting
of
the
magnetic
experience
found
Figure
a
field
field
will
in
in
circular
Combined
Current
wire
produced
magnetic
on
the
using
a
of
force.
the
wire
force
can
Fleming’s
be
left-
fields
hand
rule.
151
4.22
Electromagnetic
induction
When
LEARNING
a
conductor
through
At
the
should
end
be
of
this
able
topic
you
to:
describe
current
how
in
a
to
coil
induce
of
the
field
force
which
force
(e.m.f.).
e.m.f.

is
moved
will
lines,
attempts
If
the
produce
explain
the
the
factors
induced
the
to
electrons
make
them
conductor
an
a
magnetic
is
induced
in
the
field
so
conductor
that
it
cuts
move.
This
connected
current
in
to
the
is
a
experience
the
a
electromotive
circuit
then
the
circuit.
a
wire
Demonstrating

through
OUTCOMES
induction
affecting
To
current.
demonstrate
through
circuit
must
be
moving
wire
a
field
will
is
be
the
as
shown
very
used.
effect
small
Note
through
in
can
simple
Figure
and
that
the
you
so
the
a
4.22.1.
The
sensitive
current
magnetic
move
field.
only
a
wire
current
ammeter
exists
There
is
rapidly
when
no
induced
or
in
the
galvanometer
the
current
wire
when
is
the
stationary.
Movement
of
wire
Cutting
field
lines
Ammeter
To
understand
imagine
the
places
occurs
4.22.1
the
reason
magnetic
conductor
which
Figure
the
as
a
when
it
on
is
a
the
lines
moves.
force
there
for
field
It
the
is
induced
around
the
cutting
electrons.
relative
current
the
you
magnet
of
these
need
being
lines
Electromagnetic
movement
between
a
to
cut
of
by
force
induction
magnet
and
electromagnetic
induction
conductor
so
that
the
Investigating
It
is
to
usually
a
several
is
times
Pushing
the
in

Pulling

Reversing
will

The
also
faster
the

The
the
This
field
more
lines
magnet
are
of
than
induction
connected
field
lines
increase
(north
lines
magnet
direction
the
pole
pass
being
the
to
you
to
cut
cut.
a
move
can
use
through
into
the
the
sensitive
induced
first)
through
that
loops
of
is
that
is
of
induces
the
direction
magnet
shows
lines
the
therefore
reverse
current.
field
the
a
wire
bar
and
magnet
ammeter.
the
A
conductors
current.
solenoid
loops
of
wire
so
that
induces
the
wire
a
magnet
of
the
moving
it
is
the
cause
in
current
The
stronger

Leaving
the
There
no
is
conductor
the
magnet
magnet
relative
so
a
the
the
opposite
(pushing
in
the
direction.
south
pole)
current.
relative
rate
of
in
the
to
that
the
the
increased
solenoid
the
coil
wire
the
greater
moves
current.
greater
the
no
the
inside
larger
the
movement
field
lines
are
coil
the
does
between
being
induced
induced
not
the
cut.
current
produce
magnet
a
is.
current.
and
the
through
current.

so
wire.
the
the
the
wire)
that
field
the
out
of
magnet
magnetic
current
so
and
the
move
properties
(coil
used
magnetic
induction
to
the
solenoid
solenoid

easier
investigate
and
152
a
Demonstrating
the
The
The
direction
current
of
induced
the
in
the
current
coil
will
change
direction
as
the
magnet
is
ACTIVITY
moved
able
To
to
do
The
in
we
current
This
coil
means
that
This
the
that
end
of
the
the
the
the
rule
direction
in
a
that
work
as
current
as
the
We
need
magnet
to
be
moves.
rule:
always
the
a
field
out
current).
Use
of
acts
in
such
a
direction
as
a
magnet,
wire
to
solenoid
investigate
and
coil
induction.
to
it.
push
acts
the
solenoid
solenoid
we
coil
alternating
of
causes
magnetic
to
(an
following
when
the
coil
north
north
of
the
end
pole
the
coil
direction
of
but
the
reverses.
of
magnet
when
the
the
We
can
current
into
the
magnet
in
use
the
coil
4.22.2).
means
coil
that
and
mechanical
of
use
change
solenoid
(Figure
of
induced
the
withdrawn
the
out
determine
this
oppose
is
and
a
force
will
mechanical
work
conservation
is
of
be
work
required
must
transformed
energy
is
be
into
to
push
done
in
electrical
the
magnet
doing
energy
so.
into
This
and
so
the
law
observed.
Motion
Like
poles
repel
0
Motion
Unlike
0
Figure
4.22.2
The
solenoid
rule
allows
us
determine
the
poles
attract
direction
of
the
induced
current.
SUMMARY
QUESTIONS
1
How
can
2
How
does
a
KEY
1
you
increase
rotating
a
the
induced
magnet
at
current
the
end
of
in
a
a
solenoid?
solenoid
induce
current?
POINT
Electromagnetic
movement
current
depends
magnetic
induction
between
field
on
and
a
occurs
magnet
the
the
strength
speed
when
and
of
a
and
the
there
is
conductor.
direction
relative
relative
The
of
induced
the
movement.
153
4.23
The
d.c.
a.c.
generator
The
LEARNING
the
end
of
this
topic
be
able
direct
force
describe
d.c.
motor
the
current
on
a
motor
operation
of
a
is
not
designed
very
to
useful
cause
explain
a.c.

the
motor
wire.
effect
Making
as
a
seen
wire
in
4.21
move
in
a
to
exert
straight
a
in
most
coil
of
circumstances
wire
to
and
so
the
motor
is
rotate.
motor
Understanding

uses
current-carrying
to:
line

the
you
a
should
and
OUTCOMES
A
At
d.c.
motor
the
operation
of
generator
sketch
the
produced

an
a.c.
A
coil
The
waveform
by
the
d.c.
motor
an
of
other
generator
.
wire
magnets
and
is
mounted
are
on
arranged
produce
a
an
so
strong,
axle
that
between
the
uniform,
a
pair
of
opposite
poles
magnetic
field
magnets.
face
each
between
them.

The
coil
ring
the
is
connected
commutator
.
direction
of
to
This
the
a
circuit
allows
current
by
the
in
a
pair
coil
the
to
coil
of
connectors
rotate
to
freely
switch
called
but
every
also
a
split-
allows
half-turn.
Force

A
current
north
hand
pole
Split-ring
is
pole
rule
will

The
two

When
passed
will
to
through
experience
check
this)
experience
forces
will
a
the
an
coil.
while
the
side
downwards
cause
The
upwards
the
coil
side
force
of
of
the
(use
the
coil
coil
near
Fleming’s
near
the
the
left-
south
force.
to
rotate
on
the
axle.
commutator
the
coil
has
rotated
a
half-turn
the
commutator
will
reverse
+
Force
Metal
or
brush
contacts
graphite
the
current
the
coil
right
Figure
4.23.1
A
d.c.
motor

As
spin,
will
side
the
in
the
still
is
cause
pushed
force
Applications
of
motors
a
This
the
means
left
that
side
to
the
be
direction
pushed
of
the
upwards
force
while
on
the
downwards.
remains
producing
Electrical
coil.
in
the
turning
same
direction
moment
which
the
can
coil
be
continues
used
to
do
to
work.
motors
are
used
in
a
wide
range
of
devices
from
a
small
ACTIVITY
battery-powered
Use
an
make
electrical
your
own
motor
model
kit
of
fan
to
a
motor
which
can
drive
cars.
to
a
The
a.c.
generator
motor.
Alternating
as
seen
energy
into
in
4.22.
generators
Physically
transformation
electrical
Operation
154
current
of
the
construction

A
coil

The
coil
wire
is
they
the
are
on
electromagnetic
similar
reverse.
to
Kinetic
the
d.c.
energy
induction
motor
is
but
the
transformed
energy.
The
of
is
rely
is
of
a.c.
a
generator
simple
mounted
rotated.
a.c.
on
generator
an
axle
is
inside
shown
a
in
strong
Figure
4.23.2.
magnetic
field.
Steady
rate
of
rotation
Meter
pointer
Coil
swings
from
to
side
side
Commutator
Brushes
Alternating
rings
Figure

As
4.23.2
the
coil
An
a.c.
rotates
voltage
generator
it
cuts
through
the
magnetic
field
lines
and
a
ACTIVITY
current
is
induced.
Use
As
the
coil
rotates
through
the
field
lines
the
rate
at
which
it
to
them
changes
as
its
alignment
changes.
This
means
that
the
a
hand
produce
in
the
coil
changes
with
the
position
of
the
When
the
coil
is
horizontal
it
cuts
field
lines
at
a
generator
alternating
Describe
what
happens
coil.
when

an
e.m.f.
current.
induced
powered
cuts
high
rate
and
the
generator
is
spun
a
faster.
large

e.m.f.
When
is
the
is
produced.
coil
is
vertical
it
does
not
cut
field
lines
and
so
no
e.m.f.
induced.
During
shown
a
full
in
rotation
Figure
the
coil
will
produce
an
alternating
e.m.f.
as
SUMMARY
4.23.3.
1
Describe
QUESTIONS
the
operation
of
the
+
motor
in
battery
e.m.f.
2
1
Figure
is
4.23.1
if
the
reversed.
Comparing
the
a.c.
generator
cycle
to
0
the
d.c.
factors
motor,
beside
what
the
other
rotational
Time
will
e.m.f.
produced?
KEY
X
X
speed
increase
the
peak
POINTS
Y
Y
X
Y
N
S
1
A
d.c.
motor
electrical
Y
transfers
energy
into
kinetic
X
energy
using
the
motor
effect.
Figure
4.23.3
The
e.m.f.
produced
by
an
a.c.
generator
2
The
d.c.
motor
uses
current-carrying
which
Changing
the
rotation
the
speed
of
rotation
of
the
coil
will
cause
it
to
produce
peak
e.m.f.
It
will
also
increase
the
frequency
of
the
a.c.
a
magnetic
power
station
An
a.c.
generators
are
spun
50
times
each
a
frequency
of
50 Hz
while
others
are
spun
60
times
field.
generator
to
uses
produce
in
a
wire
by
a
rotating
each
a
second
wire
second
current
providing
of
rotate
supply.
induction
Some
coil
to
a
3
larger
made
speed
inside
Increasing
is
a
coil
inside
a
magnetic
field.
(60 Hz).
155
4.24
Transformers
The
LEARNING
voltage
called
At
the
end
should
be
of
this
able
topic
describe
the
you
best
to:
operation
of
a
an
alternating
transformer.
current.
to
cable

of
current
can
be
changed
with
a
device
OUTCOMES
When
do
will
so
The
electrical
at
high
cause
less
transformer
energy
voltage
heating
is
and
also
changes
transmitted
low
effect
over
current.
and
so
less
A
the
long
lower
energy
size
of
the
distances
current
will
be
in
it
is
the
wasted.
a
In
power
lines
the
voltages
may
be
several
thousand
volts.
transformer

state
the
difference
between
Transformer
a
step-up
and
a
A
transformer
transformer
arms

use
the
operation
step-down
transformer
of
a
consists
laminated
of
iron
two
coils
core
as
of
wire
shown
wrapped
in
Figure
around
4.24.1.
opposite
These
coils
equation.
are

the
The
primary
(input)
alternating
magnetic
field
coil
current
in
the
and
in
the
the
iron
secondary
input
coil
(output)
generates
a
coil.
varying
core.
Laminated
iron
Primar y
core
Secondar y
coil
I

The
magnetic

The
varying
output
I
p
field
is
focused
in
the
iron
core.
coil
magnetic
field
induces
an
alternating
current
in
the
coil.
s

The
iron
induced
Lamp
core
in
it.
is
laminated
These
to
‘eddy’
reduce
currents
currents
would
which
heat
the
would
core
be
and
waste
a.c.
energy.
generator

There
is
no
direct
transformer
Figure
4.24.1
The
construction
of
a
are
said
to
and
be
electrical
so
no
connection
current
can
between
pass
the
between
two
them.
coils
The
in
the
coils
decoupled
transformer
Note
that,
magnetic
The
because
fields,
it
the
transformer
There
is
a
transformer
cannot
work
operates
with
direct
by
using
changes
in
current.
equation
relationship
between
the
voltage
on
the
primary
and
the
number
coil
(V
)
p
and
the
voltage
on
the
secondary
coil
(V
)
of
turns
of
s
wire
on
the
respective
coils
(N
and
N
p
V
N
s
turns
and
see
the
that
I
p
there
currents
in
s
p
N
p
also
s
is
the
relationship
coils
(I
and
p
If
the
on
If
number
the
output
there
voltage
Figure
156
4.24.2
is
a
will
of
turns
coil
both
on
then
difference
the
there
in
the
change.
by:
=
V
can
given
I
s
=
You
)
input
will
be
I
the
number
of
).
s
coil
number
between
no
of
matches
change
turns
the
in
then
number
voltage
the
or
of
turns
current.
current
and
Step-up
Step-up
transformers
transformers
have
more
turns
on
the
secondary
coil
than
on
EXAM
the


primary
The
The
coil.
voltage
is
current
factor
as
is
This
has
two
T
ake
increased.
decreased
voltage
is
TIP
effects:
(compared
stepped
with
primary
current)
by
same
and
up.
care
check
answ
ers
WORKED
EXAMPLE
A
transformer
step-up
the
output
What
are
coil.
the
The
usin
g
the
equa
tion
that
mak
e
your
sens
e.
1
has
input
output
when
trans
fo rm
er
50
turns
voltage
on
is
the
5.0 V
input
with
coil
a
and
current
400
of
on
2.0 A.
characteristics?
ACTIVITY
Find
the
output
V
voltage
N
s
N
s
=
first:
×
V
s
;
V
400
×
5.0 V
p
Construct
=
=
=
a
simple
transformer
40 V
s
V
N
p
N
p
50
from
find
the
output
efficiency
N
p
I
s
=
and
×
N
p
;
I
of
investigate
the
device.
current:
Measure
I
cores
p
the
Now
iron
2 A
×
the
input
and
output
50
p
=
=
=
currents
0.25 A
and
voltages
and
see
if
s
I
N
s
Step-down
A
400
s
the
power
the
same.
ratings
transformer
secondary
coil.
This
has
also
more
has
turns
two
on
the
primary
coil
than
The
voltage
is
decreased.

The
current
is
increased
the
by
the
same
factor
as
the
voltage
1
is
Why
are
down
transformers
110 V
used
in
are
homes
needed
or
even
to
reduce
lower
for
transmission
step-up
some
How
EXAMPLE
many
turns
transformer
the
primary
V
in
of
electrical
devices.
2
What
order
coil
has
V
s
=
are
N
the
on
the
voltage
secondary
from
200 V
coil
to
of
6.0 V
a
if
×
N
×
in
is
the
output
is
40 V
if
voltage
the
and
input
there
are
400
turns
on
the
primary
and
2500
on
the
secondary
Is
down
6.0 V
step-
used
distribution?
transformer
coil?
turns?
s
;
required
lower
500
N
s
to
a
voltage
2
wire
and
transformers
voltages
of
WORKED
are
QUESTIONS
electricity
to
IV)
effects:
down.
Step-down
=
on
SUMMARY

stepped
(P
transformers
step-down
the
N
p
this
a
step-up
or
coil
step-
transformer?
500
p
=
=
=
15
turns
s
V
N
p
V
p
200 V
p
KEY
Transformer
power
1
The
relationship
secondary
output
between
voltage
power
POINTS
of
a
and
the
primary
current
can
transformer
as
voltage
be
used
and
to
find
current
the
and
input
the
transformer
increase
and
voltage
;
V
I
s
=
V
s
I
The
p
V
p
N
a.c.
supply.
equation
IV
P
p
=
N
p
as
we
have
the
=
out
I
p
s
relationship:
3
Transformers
are
very
P
in
efficient
and
so
P
=
out
above
equation
transformer
and
so
the
is
is
actually
equation
is:
s
V
The
to
the
I
s
=
I
p
defined
an
transformer
s
V
is
used
p
=
power
of
is
decrease
I
s
As
or
follows:
2
V
A
used
a
can
for
highly
be
an
‘ideal’
efficient
used
to
transformer.
device
find
with
results
However,
low
close
to
power
true
a
loss
provides
results
close
P
in
to
true
values.
values.
157
Section
SECTION
1
The
4:
Practice
resistance
given
by
4
the
of
a
Practice
exam
set
of
questions
resistors
in
exam
parallel
is
4
relationship:
1
1
=
A
+
R
P
R
1
student
strength
it
by
+
…
group
of
resistors
in
by
using
the
relationship
electromagnet
the
magnet
to
between
and
lift
a
the
the
current
chain
of
steel
paper
clips
from
a
desk.
The
results
are
3
students
relationship
an
R
2
shown
A
tested
of
1
+
R
3
3
in
1
questions
were
placing
parallel
a
with
asked
to
number
each
verify
of
in
the
table.
this
Current/A
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Paper
1
3
4
5
7
8
11
13
15
60 Ω
other.
They
clips
then
lifted
measured
potential
the
current
difference
through
across
the
set
and
the
them.
a
Plot
a
graph
paper
Number
Theoretical
Current
Potential
Measured
of
resistance
/A
difference
resistance
resistors
/Ω
/V
/Ω
0.19
12.0
2
0.38
12.0
3
0.57
12.0
4
0.76
12.0
5
A
Describe
group
factor
of
The
factors:
Sketch
the
five
arrangements
of
Calculate
set
the
of
Calculate
set
d
of
Plot
theoretical
resistance
the
e
graph
measured
resistance
of
to
the
difference
results
comparing
the
the
measured
theoretical
resistance
the
magnets
Mass
their
effect
how
large
on
electromagnet.
electromagnet
investigated
the
a
was
mass
two
current
of
loops
of
wire.
in
the
three
it
could
different
and
They
tables
causes
the
of
the
effect
to
of
each
of
loops
of
wire
lifted/g
Current
possible
and
next
of
increasing
recorded
shown.
0.5 A
10
15
20
25
1.1
1.3
1.5
1.7
the
10
15
20
25
2.2
2.6
3.0
3.4
10
15
20
25
3.3
3.9
4.5
5.1
1.0 A
Number
of
loops
of
wire
measured
theoretical
lifted/g
resistance.
Current
Describe
greatest
which
of
Mass
2
the
testing
students
Number
between
resistance
of
by
the
investigating
each
combinations.
Describe
of
the
for
resistors.
a
in
resistors.
the
resistance
number
shown.
was
strength
increasing
Current
c
pattern
have
the
number
their
each
the
current
resistors.
the
b
the
12.0
lift.
a
to
students
strength
measured
0.95
the
would
increasing
The
5
comparing
lifted
electromagnet.
b
1
clips
placing
other
two
in
all
1.5 A
bar
six
possible
Number
of
loops
of
wire
orientations.
Mass
3
Which
of
these
will
increase
the
strength
of
lifted/g
an
a
electromagnet?
Why
should
during
a
Increasing
b
Reversing
c
Replacing
the
current
in
the
direction
of
the
iron
core
with
the
the
students
use
an
iron
core
experiments?
What
conclusions
can
be
made
about
the
current.
effect
the
of
coil.
b
the
all
an
of
increasing
the
current?
aluminium
c
What
conclusions
can
be
made
about
the
core.
effect
d
Increasing
the
number
of
turns
of
wire
in
wire?
the
e
coil.
Switching
rapidly.
158
the
electromagnet
on
and
off
of
increasing
the
number
of
loops
of
6
A
bar
magnet
shown
there
in
to
the
be
is
inserted
diagram.
a
current
into
An
in
a
solenoid
ammeter
the
wire
as
as
a
Which
b
What
way
will
the
motor
rotate?
shows
is
the
function
of
the
split-ring
the
commutator?
magnet
moves.
c
How
can
the
power
of
the
motor
be
increased?
Hollow
cardboard
tube
8
Y
X
What
are
increase
the
the
factors
e.m.f.
that
of
an
can
a.c.
be
used
to
generator?
N
S
9
An
a.c.
generator
revolves
with
a
frequency
Magnet
of
20 Hz
voltage
a
a
What
is
causes
the
a
name
current
of
in
the
the
process
What
will
happen
to
of
produces
an
e.m.f.
with
a
peak
voltage–time
graph
showing
50 V
.
Sketch
a
supply
provided
the
which
by
this
generator.
wire?
The
b
and
the
reading
on
frequency
of
the
generator
is
increased
to
the
40 Hz.
meter
when
the
magnet
is
pulled
out
of
b
the
Sketch
how
c
What
will
magnet
happen
is
to
inserted
the
more
reading
if
current
in
the
solenoid
causes
it
10
An
ideal
being
d
e
of
a
magnetic
will
the
What
field
when
the
magnet
transformer
a.c.
mains
is
graph
showing
change.
used
voltage
resistance
to
to
convert
power
a
a
12 V
lamp
5 Ω
a
What
is
the
current
be
the
magnetic
polarity
of
b
What
is
the
power
c
What
is
the
current
in
the
lamp?
solenoid?
will
be
solenoid
the
direction
(clockwise
or
of
the
motor
is
constructed
as
the
lamp?
current
in
the
primary
coil?
in
A
transformer
has
500
turns
on
the
primary
coil
anticlockwise)?
6000
current
d.c.
of
end
and
A
would
is
11
the
7
voltage–time
inserted.
What
X
new
supply
to
with
produce
the
the
quickly?
110 V
The
a
solenoid?
shown
in
on
the
when
the
output
coil.
primary
What
current
is
is
the
output
0.2 A.
the
diagram.
12
The
diagram
using
current
of
a
the
shows
step-up
in
the
and
132 kV
transformers
calculate
an
electrical
step-down
cable
are
is
distribution
transformers.
0.2 A.
grid
The
Assuming
all
ideal:
the
current
from
the
current
that
the
power
station
b
calculate
can
be
provided
+
to
light
industry.
+
To
power
source
Transformer
Transformers
132 kV
25 kV
33 kV
11 kV
230 V
Light
industr y
Factories
159
5
The
physics
5.1
of
Models
Initial
LEARNING
the
end
of
this
topic
be
able
summarise
of
models
civilisations,
substances
describe
the
of
the
describe
the
the
until
such
the
the
substances
smallest
development
as
the
Greeks,
simplest
used
components
the
idea
were
of
cutting
reached.
These
parts
were
possible:
‘elemental’
and
were
built
from
the
atoms.
atom
‘plum
pudding’
model
Geiger–Marsden
experiment

atom
to:
The

the
ideas
simplest

of
you
up
should
atom
OUTCOMES
Ancient
At
the
At
modern
view
the
end
discovered
of
of
(electrons).
atom.
from
inside
possible
As
Sphere
a
positive
19th
century
heating
Thomson
the
atoms
metals
the
proposed
and
British
could
that
therefore
physicist
release
the
the
J.
small
electrons
atom
J.
Thomson
particles
were
was
not
released
the
smallest
particle.
beam
fields,
of
the
that
of
electrons
Thomson
original
atom
could
realised
was
be
that
deflected
the
uncharged,
by
electrons
he
magnetic
were
proposed
a
and
charged.
model
electric
As
where
the
the
charge
electrons
in
‘sponge’.
(Figure
an
This
atom
was
were
the
trapped
‘plum
inside
pudding’
a
positively
model
of
the
charged
atom
5.1.1).
Electrons
Rutherford
Figure
5.1.1
The
‘plum
pudding’
and
the
nuclear
model
model
A
few
years
students,
structure
charged
later
Hans
of
Ernest
Geiger
an
atom,
particles)

most
passed

some
were

some
bounced
Rutherford
and
Ernest
using
(Figure
a
asked
beam
5.1.2).
two
Marsden,
of
alpha
When
straight
through
the
foil
deflected
through
large
of
to
his
research
investigate
particles
fired
at
with
a
a
thin
very
the
(positively
gold
small
foil:
deflection
Incident
α-particles
Atoms
in
the
metal
angles
foil
+
straight
back.
+
These
results
could
not
be
explained
by
the
plum
pudding
model
and
+
so
Rutherford
proposed
a
new
model
‘the
nuclear
model’.
+
+

As
most
of
the
alpha
particles
pass
straight
through,
most
of
the
Nucleus
+
atom
α-particle
must
be
composed
of
empty
space.
tracks
+

As
some
alpha
particles
are
deflected
they
must
be
repelled
by
+
a
dense
positively
nucleus)
Figure
5.1.2
The
deflection
paths
which
charged
contained
part
of
the
protons
atom
and
(later
most
of
named
the
the
mass
of
the
of
atom.
alpha
gold
particles
foil
fired
at

The
apparent
size
of
was
a
160
the
radius
nucleus.
suggested
way
similar
that
to
the
of
As
atoms
the
they
was
much
electrons
occupied
planets
the
orbiting
greater
were
known
space
the
than
to
around
Sun.
the
be
measured
very
the
small,
nucleus
it
in
The
The
of
Bohr
model
previous
the
models
electrons
and
electromagnetic
Bohr
suggested
(shells
were
or
of
of
atom
the
why
atom
they
could
did
not
not
fall
explain
into
the
the
behaviour
nucleus
due
to
forces.
that
energy
possible
the
the
levels).
and
this
electrons
Only
could
certain
prevented
only
occupy
transitions
the
electrons
certain
between
from
regions
these
falling
shells
into
the
Nucleus
nucleus.
Discovery
In
1932
James
neutron),
(Figure
Our
of
of
neutrons
Chadwick
similar
discovered
mass
to
the
that
proton,
an
uncharged
existed
within
particle
the
(the
nucleus
5.1.3).
understanding
of
the
structure
of
the
atom
continues
to
develop
Electrons
through
the
standard
model,
where
the
forces
binding
the
around
together
of
are
explained,
subatomic
particles
and
are
quantum
described
mechanics,
as
complex
where
in
the
the
Figure
5.1.3
2
the
pudding’
a
what
charge
b
what
is
c
what
force
a
the
the
why
do
electrons
remainder
holds
the
of
did
most
of
the
an
atom
electrons
Geiger–Marsden
without
KEY
1
why
were
in
composed
of?
place?
ACTIVITY
experiment:
alpha
particles
pass
through
the
gold
an
online
simulator
to
deflection?
some
The
concept
Scientists
that
in
of
the
The
developed
modern
containing
‘shells’
or
matter
ancient
experimentation
3
the
alpha
particles
directed
straight
back?
scattering
the
Rutherford
experiment.
POINTS
developed
2
of
have?
reproduce
b
model
model:
Use
foil
nuclear
QUESTIONS
‘plum
During
The
atom
SUMMARY
In
nucleus
positions
mathematical
probabilities.
1
orbit
nucleus
view
of
energy
composed
models
and
protons
is
of
atoms
was
initially
Greece.
of
analysis
the
and
the
of
atom
atom
through
evidence.
has
neutrons,
a
central
nucleus
surrounded
by
electrons
in
levels.
161
5.2
Electrons,
and
The
LEARNING
At
the
should
end
be
of
this
able
compare
of
nucleus
periodic
components
of
table
atoms
OUTCOMES
topic
Experiments
have
particle
make
the
electrons,
now
shown
that
there
are
three
different
types
of
you
that
up
all
atoms
(T
able
5.2.1).
to:
T
able

the
the
5.2.1
Properties
of
subatomic
particles
properties
protons
and
Particle
Location
Mass
proton
in
1
Electric
charge
neutrons

identify
the
constituents
the
nucleus
unit
+1 e
of
−27
(1.67
×
10
×
10
−19
kg)
(1.60
×
10
C)
isotopes
neutron

describe
the
in
the
nucleus
1
unit
−27
(1.67
between
atomic
structure
periodic
kg)
0 C
and
electron
the
0
relationship
outside
the
1
−1 e
table.
−19
nucleus
in
~
energy
unit
(−1.60
×
10
C)
2000
levels
or
‘shells’
−31
9.11
Neutral
atoms
protons
and
have
the
neutrons
same
are
×
number
found
in
10
of
the
kg
electrons
nucleus
and
they
protons.
are
referred
As
to
as
nucleons
Nuclear
A
EXAM
nucleus
Very
specifi
c
used
in
phys
ics.
unde
key
can
be
described
using
the
number
of
protons
and
TIP
neutrons
is
notation
Mak
e
rstand
,

sure
all
The

The
nucleus.
of
protons,
number)
total
is
number
the
proton
represented
of
nucleons
by
number
the
letter
(protons
and
(also
called
the
Z
neutrons)
is
called
the
you
nucleon
of
the
number
atomic
nucle
ar
wo rd
s,
nucle
us
lang
uage
in
number
(or
sometimes
mass
number)
and
is
represented
the
by
the
letter
A
especia
lly
nucli
de
and

iso to
pe.
The
the
number
letter
of
neutrons,
the
neutron
number,
is
represented
by
N
A
X
Z
The
neutron
found
number
simply
number
of
by
is
not
normally
recorded
because
it
can
be
remembering:
neutrons
=
mass
number
−
atomic
number
(N
=
A
−
Z)
Examples
ACTIVITY

Use
a
periodic
table
to
A
nucleus
of
magnesium
with
an
atomic
number
of
12
and
24
study
number
of
24
is
represented
by
Mg.
12
the
patterns
in
electron

arrangement
and
the
A
nucleus
of
patterns
chemical
elements
in
behaviour
the
same
by
protons
and
5
neutrons
is
B.

A
nucleus
of
iron
containing
56
represented
by
Fe.
26
162
5
5
of
group.
containing
10
represented
of
boron
26
protons
and
30
neutrons
is
a
mass
Isotopes
WORKED
Nuclei
of
a
single
element
always
have
the
same
number
of
protons
Sketch
and
so
have
the
same
atomic
number.
However,
the
nuclei
may
different
number
of
neutrons.
For
example,
most
carbon
six
protons
and
six
neutrons
but
some
carbon
isotopes
structure
of
for
boron
B
5
nuclei
nuclei
atomic
10
two
11
and
contain
the
have
the
a
EXAMPLE
B.
5
contain
5
seven
neutrons
or
even
eight.
×
Nucleus
Atoms
are
with
called
the
same
proton
number
but
different
nucleon
numbers
×
1
0
isotopes
B
Three
isotopes
of
carbon
are:
13
C
5
neutrons
14
C
6
protons
×
5
12
with:
5
C
6
×
6
×
As
the
proton
number
identifies
the
name
of
the
element
it
is
often
Both
more
convenient
carbon-13
Nuclei
or
that
to
write
isotopes
in
a
simpler
format:
carbon-12,
5
carbon-14.
share
the
same
number
of
protons
and
neutrons
isotopes
have
electrons:
2
in
the
first
3
in
the
second
shell
shell
are
5
referred
to
as
nuclides.
×
Nucleus
×
with:
5
protons
6
neutrons
1
1
Patterns
in
electron
shells
and
the
periodic
×
B
table
5
×
The
periodic
table
is
arranged
in
order
of
proton
number
from
left
×
to
right
in
shells
the
and
(or
working
energy
behaviour
outermost
of
down
levels)
through
and
elements
the
with
the
periods.
periodic
the
same
table
Electrons
shows
number
of
a
are
found
pattern
electrons
in
in
Figure
shell.
KEY
Each
for
complete
an
5.2.1
the
energy
period
in
the
periodic
table
represents
the
filling
POINTS
up
level.
1
Atoms
are
because

The
are

first
2
The
shell
can
elements
second
in
shell
contain
the
can
first
a
maximum
of
2
electrons
and
so
The
third
shell
can

equal
number
of
positive
charged
contain
up
to
8
protons
to
negatively
electrons.
contain
up
to
8
electrons
and
the
fourth
up
electrons.
to
Mass
number
(A)
=
atomic
electrons.
For
example,
arrangement
a
silicon
is
atom
has
14
electrons
and
the
number
(Z)
number
(N)
Isotopes
in
of
same
the
elements
number
nucleus
numbers
of
but
of
have
protons
different
neutrons.
QUESTIONS
Fluorine
has
number
of
a
proton
2
Copy
T
able
5.2.2.
Then
calculate
and
fill
in
the
missing
values.
9.
T
able
a
neutron
electron
the
SUMMARY
+
2,8,4.
3
1
particles
an
period.
2
18
are
there
charged

neutral
there
How
many
does
a
5.2.2
electrons
neutral
Number
fluorine
of
Nucleon
Number
of
Number
of
Atom
atom
b
Sketch
of
c
In
protons,
have?
the
these
what
periodic
placed?
arrangement
a
carbon
b
sodium
c
gold
d
osmium
6
Z
number
,
A
neutrons,
N
electrons
12
electrons.
group
table
of
is
11
12
the
197
79
fluorine
76
114
163
5.3
Radioactive
A
LEARNING
short
the
end
of
this
topic
1896
Henri
be
able
in
describe
three
the
properties
nuclear
of
the
which
Marie
radiations
in

know
the
sources
background
a
drawer
noticed
near
some
that,
after
leaving
photographic
a
film,
sample
the
film
containing
became
to:
exposed.

Becquerel
you
uranium
should
history
OUTCOMES
In
At
emissions
of
He
theorised
caused
and
a
Pierre
sufficient
that
chemical
Curie
amounts
the
uranium
reaction
in
investigated
to
allow
the
was
the
producing
film.
other
study
Over
minerals
of
its
the
‘invisible
next
and
few
isolated
rays’
years
radium
properties.
some
radiation.
Background
There
us
is
always
from
Nuclear
a
natural
radiation
radiation
varies
small
and
amount
artificial
from
place
of
background
sources
to
place.
(Figure
Some
radiation
5.3.1).
locations
The
around
level
have
of
more
this
than
weapons
twenty
times
the
level
of
radiation
as
others.
0.4%
Food
Air
and
travel
Cosmic
0.3%
drink
Investigating
13.0%
15.6%
nuclear
radiation
Nuclear
reactors
Three
different
types
of
nuclear
radiation
have
been
discovered:
Ground
0.1%
16.0%
Air
alpha
(α),
beta
As
nuclear
(β)
and
gamma
(γ).
33.6%
Medical
21.0%
the
material
it
stripped
away
Alpha
Figure
5.3.1
Typical
origins
cause
from
particles
are
interacts
with
ionisation,
their
the
where
atoms
some
of
or
molecules
the
electrons
most
pass
A
They
are
atoms.
strongly
charged
absorbed
penetrating
and
this
makes
them
interact
easily
By
of
absorbed
by
all,
as
they
less
materials.
easily
interact
and
Beta
particles
least
gamma
with
the
rays
counter
can
particle
electrical
placing
counter,
pulse
used
which
different
the
be
passing
is
penetrating
to
detect
through
logged
materials
a
by
can
G–M
ionising
matter
radiation.
Geiger–Müller
a
between
power
Source
be
counter
the
tube
attached
source
and
investigated
A
to
the
radioactive
safety
(Figure
tube
rules
handling
sources.
Explain
why
Support
these
rules
are
needed
when
or
Plasticine
Set
handling
the
different
types
range
to
give
a
large
of
Fixed
distance
enough
deflection
sources.
Figure
164
5.3.2
Measuring
the
penetrating
powers
of
nuclear
the
tube.
Geiger
ACTIVITY
the
the
they
produces
Ratemeter
when
are
are
through.
Geiger
an
and
penetrating
radioactive
required
a
radiation
more
Investigate
of
are
of
strongly.
background
radiation
can
radiations
5.3.2).
Effect
of
magnetic
and
electric
fields
a
Beam
Charged
particles
experience
a
force
when
they
move
a
magnetic
or
electric
fields
(Figure
5.3.3).
The
size
and
direction
of
depends
upon
the
charge
of
the
particle.
Alpha
particles
mass
than
beta
particles
so
do
not
deflect
as
magnetic
easily.
Also
alpha
will
curve
in
the
opposite
direction
to
beta
particles
have
opposite
charge.
Gamma
rays
are
not
affected
by
right
to
plane
because
of
they
at
angles
the
particles
enters
field
have
field
more
radiation
magnetic
the
A
force
of
through
the
the
fields
paper
as
they
T
able
are
not
5.3.1
charged.
Properties
of
alpha,
beta
and
gamma
β-radiation
radiation
α-radiation
deflected
deflected
Alpha
particles
Beta
particles
Gamma
in
the
by
opposite
rays
the
is
is
direction
magnetic
to
α-radiation
field
Symbol
α
β
γ-radiation
γ
by
Nature
A
particle
A
fast
moving
the
is
undeflected
magnetic
field
Electromagnetic
b
consisting
of
electron
ejected
radiation
Electric
two
protons
and
from
the
emitted
by
field
positive
two
neutrons
ejected
from
nucleus
nucleus.
the
energy
A
between
the
and
negative
high
α
metal
plate
Beam
of
photon.
γ
nucleus
radiation
β
Electric
+2 e
(charge
of
−1 e
(charge
of
None
+
charge
two
protons)
one
electron)
Penetrating
Can
travel
Can
travel
power
only
Note
that
electric
a
few
metres
centimetres
in
in
Blocked
a
few
Can
air.
travel
distance
by
α-
field
and
are
β-particles
deflected
in
passing
in
air.
Figure
5.3.3
Radioactive
passing
Intensity
metal
foil.
reduced
by
paper
by
or
Ionising
Strongly
power
ionising
is
such
Ionising
as
massive
highly
metal
skin.
of
alpha
ionisation
and
the
Deflects
particle
beta
the
No
electric
the
particle
fields
in
Why
would
to
alpha
chamber
we
they
cannot
make
see
when
α
or
water
β
particles
droplets
or
γ-rays,
condense
we
on
can
ions
see
the
formed
in
careers
you
than
average
having
a
annual
of
radiation?

Radiographer

Airline

Miner
in
a
hospital
pilot
a
2
cloud
to
particle
dose
tracks
lead
an
higher
Although
these
opposite
direction
cloud
QUESTIONS
effect
possibly
The
an
it
1
and
b
field
charged
Deflects
magnetic
a
lead.
SUMMARY
Effect
a
and
plating
as
Some
field
thick
electric
Blocked
an
directions
emissions
through
magnetic
air.
through
opposite
long
What
type(s)
of
nuclear
chamber.
radiation:
KEY
1
a
can
penetrate
b
causes
There
are
three
types
of
nuclear
radiation:
alpha,
beta
skin?
the
c
are
deflected
magnetic
There
and
is
always
artificial
some
sources.
background
radiation
from
both
most
ionisation?
and
gamma.
2
your
POINTS
by
a
field?
natural
d
can
travel
farthest
in
air?
165
5.4
Nuclear
and
reactions
Unstable
LEARNING
the
end
of
this
topic
nuclides
be
able
describe
a
the
nucleus
changes
decay
or
time.
a
nuclear
construct
nuclear
not.
them
For
have
example,
a
emits
an
nucleus
not
break
has
the
apart.
correct
However,
many
neutrons
causing
carbon-12
nuclei
will
or
the
nucleus
is
stable
a
decay
over
too
to
many
decay
nuclide
time
protons
(break
but
and
apart)
carbon-14
changing
into
this
over
is
nitrogen-14
decay
occurs
new
it
can
be
described
in
these
simple
terms:
nucleus
→
daughter
nucleus
+
α,
β,
or
γ
alpha
decay
an
unstable
parent
nucleus
releases
two
protons
α-particle
and
a
the
does
decay
During
forms
that
and
changes.
Alpha
and
means
equations
nuclear
parent
nucleus
This
neutrons
too
unstable
Carbon-14
When
describing
The
and
nuclei.
reaction

stable.
protons
nuclides
makes
in
undergoing
radioactive
of
to:
some

are
you
balance
should
isotopes
OUTCOMES
Many
At
decays
two
neutrons
bound
together
forming
an
alpha
particle
(Figure
nucleus
5.4.1).
a
The
daughter
nucleus
alpha
particle
nucleus
the
with
resulting
is
ejected
less
mass.
daughter
is
a
from
As
the
two
parent
protons
different
nucleus
have
element
left
than
leaving
the
the
parent.
α-particle
The
general
form
of
an
alpha
A
X
→
α
Z
Proton
5.4.1
Alpha
particle
beta
was
EXAMPLE
particle
not
proton
1
is
the
alpha
decay
decay
equation
isotope
a
is
a
fast
proton
originally
the
present.
nucleus
from
the
moving
inside
and
→
84
of
After
so
general
form
of
a
beta
α
+
A
β-particle
created
in
is
nucleus
or
beta
energy.
may
cause
nucleus
decay
equation
is
electron
additional
a
different
is:
→
A
β
+
–1
Y
Z
+
1
be
any
and
decay
The
released
change
so
may
nucleus
the
by
in
the
to
daughter
be
in
an
a
gamma
decay.
the
number
of
product
of
the
Gamma
protons
decay
is
nucleus
excited
the
or
nuclide.
general
form
of
a
gamma
A
X
Z
the
changes
proton
emission
decay
0
→
γ
0
equation
A
+
X
Z
is:
with
state.
decay
some
This
does
neutrons
same
emitted
The
particle
said
and
instantly
Beta
leave
is
the
parent
166
nuclide
an
decay
alpha
not
5.4.2
is
neutron
Pb
energy
Figure
there
a
The
82
excess
a
daughter
0
X
An
into
the
decay
when
5.4.2).
parent.
lead?
Gamma
nucleus
the
produced
(Figure
206
2
in
nucleus
polonium-210
4
neutron
2
electron
the
Z
210
A
–
Y
2
A
Po
Z
+
is:
for
The
of
to
in
element
What
an
4
decay
converts
into
–
emission
A
WORKED
equation
A
Neutron
Beta
Figure
decay
4
in
element
the
as
the
Other
nuclear
reactions
WORKED
Nuclear
nuclei
process
is
induced
can
split
usually
fission.
becomes
so
into
caused
The
two
by
smaller
hitting
neutron
unstable
that
it
is
nuclei,
the
nucleus
absorbed
splits
up.
releasing
and
During
with
then
a
energy.
neutron
the
fission
This
in
beta
nucleus
several
a
decay
caesium-137
of
neutrons
decay
reactors
chain
alongside
these
the
neutrons
two
are
new
used
to
nuclei
cause
(Figure
further
5.4.3).
fissions
In
form
for
undergoes
an
isotope
barium.
137
0
Cs
released
equation
which
to
→
137
β
55
are
2
fission
Write
Large
EXAMPLE
+
Ba
–1
56
nuclear
and
form
a
reaction
235
1
U
141
+
n
92
→
92
Ba
0
+
1
Kr
56
+
3
36
n
0
Fission
Target
2
product
1
H
H
1
1
nucleus
Neutron
Fission
product
γ
3
He
2
Figure
5.4.3
Nuclear
Nuclear
Figure
fission
5.4.4
Nuclear
fusion
fusion
ACTIVITY
Stars
this
produce
process
(Figure
their
small
5.4.4).
processes,
isotopes.
An
nuclei
The
mostly
energy
Sun
are
2
the
of
all
isotopes
a
fusion
1
process
merged
produces
fusing
example
using
of
of
together
of
its
to
form
energy
hydrogen
reaction
nuclear
is
to
by
larger
nuclear
form
shown
fusion.
In
ones
fusion
helium
below.
Most
nuclear
place
in
there
have
formed
H
+
H
→
1
SUMMARY
Write
He
+
KEY
decay
equations
for
the
The
alpha
reactors.
Find
but
naturally
and
how
they
out
about
worked.
decay
of
americium-241
POINTS
Alpha
decay
involves
the
following.
241
a
some
γ
QUESTIONS
complete
been
2
1
1
takes
reactors
3
these
1
fission
nuclear
(
release
Am)
into
an
of
an
alpha
particle
isotope
95
(helium
of
neptunium
parent
137
b
The
beta
nucleus)
from
a
(Np).
decay
of
caesium-137
(
Cs)
into
an
isotope
nucleus.
of
55
2
Beta
decay
involves
the
barium.
release
2
Copy
and
complete
these
nuclear
fission
and
fusion
of
adding
the
missing
values
for
proton
number
beta
particle
equations
(electron)
by
a
and
when
a
neutron
nucleon
converts
to
a
proton
in
a
number:
nucleus.
235
a
1
U
+
92
2
b
→
+
+
→
?
He
?
+
1
Sr
?
4
H
1
90
Xe
54
?
H
1
?
n
0
+
2
n
0
3
Gamma
changes
decay
in
the
involves
energy
nucleus.
n
?
167
5.5
A
model
of
radioactive
decay
Radioactive
LEARNING
Radioactive
At
the
end
of
this
topic
be
able
of
describe
a
simple
simulate
of
a
the
random
an
number
of
discuss
the
are
process
but,
involved,
because
the
decay
a
very
process
large
can
be
fairly
simply.
effective
model
of
the
decay
process
all
of
the
particles
need
to
be
identical
so
that
they
each
have
exactly
the
objects
same

random
decay
involved
large
a
nuclei
experiment
For
to
is
identical
to:
modelled

decay
you
number
should
decay
OUTCOMES
limitations
of
chance
of
decaying.
In
the
model
all
of
the
particles
(dice)
are
the
identical
(Figure
5.5.1).
They
all
have
the
same
chance
of
decay
as
model.
each
other
Follow
decay
when
the
they
procedure
and
the
are
rolled.
described
patterns
in
the
Activity
to
gather
data
about
produced.
ACTIVITY
1
Put
60
2
Make
dice
sure
5.5.1
A
large
can
be
number
used
radioactive
to
of
If
you
have

If
you
are
3
Roll
all
4
Remove
simulate
decay.
Results
table
Roll
Dice
Dice
Dice
Dice
number
left
left
left
left
0
60
Try
1
Try
These
side
but
Record
2
Try
3
6
Roll
7
Repeat
60
all
have
or
is
box
so
that
marked
cubes
normal
you
clearly
then
don’t
on
colour
numbered
one
in
a
dice
lose
them.
face.
spot
then
on
the
one
face.
number
six
spot.
dice,
a
handful
at
a
time.
do
the
of
dice
dice
not
lose
number
in
a
the
dice
end
of
dice
and
like
upwards
Put
the
(or
showing
decayed
dice
to
a
the
(not
the
T
able
number
of
dice
that
5.5.1.
dice.
recording
or
spot
left
table,
remaining
left
up
‘decayed’.
them.
results
rolling
no
that
have
you
the
have
number
rolled
20
of
dice
left
until
you
times.
T
otal
8
60
simple
the
any
six).
decayed)
5.5.1
dice
using
as
the
tray
dice
5
T
able
a
each

counts
Figure
in
Repeat
the
whole
process
from
stage
3
two
times
to
fill
in
the
180
results
table.
1

The
more
sets
of
rolls
you
complete
the
better
the
final
2
graph
will
be.
If
you
do
not
have
time
for
three
sets
then
3
you
may
share
results
or
just
use
one
or
two
sets.
…
9
Work
out
the
total
number
of
dice
left
for
each
roll
19
by
20
168
adding
the
three
sets
of
results
across
the
table.
number
T
able
Analysing
the
You
see
should
5.5.2
Example
results
data
that
the
three
sets
of
data
are
not
identical
although
Roll
Dice
remaining
number
the
pattern
enough
of
Producing
Plot
a
a
label
of
A
should
axes
graph
remain
This
shows
process
that,
follows
when
using
predictable
large
patterns.
the
a
is
called
plot
the
number
the
smooth
this
to
roll
on
y-axis.
curve
an
on
the
Add
a
following
exponential
graph
x-axis
line
but
you
of
the
total
fit
pattern
decay
must
and
best
of
curve.
make
to
the
You
sure
used
certain
You
Eight-
T
en-
sided
sided
sided
dice
dice
dice
0
6000
6000
6000
1
5000
5250
5400
2
4167
4594
4860
3
3472
4020
4374
4
2894
3517
3937
5
2411
3077
3543
6
2009
2693
3189
7
1674
2356
2870
8
1395
2062
2583
9
1163
1804
2325
10
969
1578
2092
11
808
1381
1883
12
673
1209
1695
13
561
1057
1525
14
467
925
1373
15
389
810
1235
16
325
708
1112
17
270
620
1001
18
225
542
901
19
188
475
811
20
157
415
729
can
that
you
graph
be
a
Six-
the
clearly.
can
questions.
with
be
like
the
after
similar.
decay
remaining
curve
Analysing
The
graph
spreadsheet
the
is
the
graph
dice
This
points.
use
a
scatter
number
graph.
decay
numbers,
may
to
determine
number
use
of
what
rolls.
fractions
of
a
fraction
Use
the
of
the
graph
to
original
answer
dice
these
roll.
1

How
many
rolls
did
it
take
to
get
down
to
the
original
number
of
2
dice?
1

How
many
more
rolls
to
get
down
to
of
the
original?
of
the
original?
4
1

How
many
more
rolls
to
get
down
to
8
You
should
remaining
see
dice
Limitations
Because
results
do
entirely
for
If
the
you
a
a
to
of
halve
the
limited
not
dice
to
The
is
always
number
and
number
of
rolls
required
for
the
3.8.
model
follow
smooth
use
pattern.
this
you
halve
or
dice
pattern
may
each
thousands
of
were
used
exactly.
find
that
it
you
The
did
may
decay
not
find
curve
take
that
may
exactly
your
not
3.8
be
rolls
time.
millions
of
dice
the
curve
would
be
much
SUMMARY
smoother
and
monitoring
the
the
relationship
decay
of
would
radioactive
be
more
nuclei
precise.
there
are
generally
1
billions
of
nuclei.
Even
though
the
decay
of
an
individual
nucleus
a
Plot
there
is
a
consistent
pattern
to
the
number
of
a
dice
after
a
certain
types
b
results
the
5.5.2
shows
the
Do
example
(idealised)
results
produced
the
experiment
with
6000
dice.
You
may
use
this
data
graphs
if
you
don’t
all
of
have
enough
dice.
The
table
also
that
would
be
obtained
when
using
eight-
and
shows
the
ten-sided
How
may
the
rolls
dice
pattern
does
number
How
dice
of
it
take
eight-
to
many
halve?
rolls
for
the
POINTS
number
The
random
model
the
‘decay’
decay
of
of
large
numbers
of
dice
can
be
used
to
to
Although
pattern
in
the
the
of
ten-sided
dice
halve?
nuclei.
2
2
same
of
dice.
d
1
types
the
sided
KEY
the
decay?
for
results
all
to
c
plot
for
shown
by
of
completing
dice
table.
follow
T
able
of
time.
in
Example
showing
remaining
nuclei
three
remaining
graph
is
the
unpredictable
QUESTIONS
When
decay
decay
of
of
a
single
large
dice
cannot
numbers
can.
be
predicted
the
Why
are
after
twenty
sided
the
there
dice
more
rolls
when
six-sided
for
dice
left
the
ten-
compared
to
dice?
169
5.6
Nuclear
decay
and
half-life
Rate
LEARNING
of
Although
At
the
end
of
this
topic
be
able
define
the
half-life
radioisotope
activity
or
isotope
in
of
a
find
a
terms
amount
of
of
the
model
to
predict
of
decay
time
when
nuclide
will
a
specific
decay
nucleus
decays
exponentially
in
is
the
random,
same
way
a
large
as
the
described
the
is
in
5.5.
behaviour
not
affected
of
by
This
a
regular
sample
external
of
decay
pattern
radioactive
conditions
can
be
material.
such
as
used
The
rate
temperature
or
pressure.
remaining
Decay

of
to:
dice

the
you
sample
should
decay
OUTCOMES
the
half-life
radioisotope
of
from
constant
a
a
graph.
The
decay
constant
decay
in
in
model.
the
one
likelihood
nuclei
exactly
have
second.
of
have
the
Some
very
same
the
a
nuclide
This
is
nuclei
decaying
a
exactly
of
decay
same
similar
are
and
small
is
so
to
very
a
All
constant.
chance
of
likelihood
the
chance
unstable
have
chance.
the
large
nuclei
For
and
of
dice
a
same
all
each
a
will
‘decaying’
high
constant
the
example,
decaying
nucleus
have
decay
of
a
while
nuclide
carbon-14
other
have
nuclei
second.
Activity
The
activity
This
of
is
the
nuclei
left,
the
Decay
A
of
is
of
showing
gniniamer
over
a
a
nuclei
sample
that
is
the
decay
proportional
sample
of
ielcuN
graph
the
period
remaining
falls
but
remaining
time
remaining
never
showing
because
number
of
to
rate
each
the
over
the
the
a
of
decay
second.
number
period
(Figure
radioactive
called
zero
a
but
of
of
As
of
the
the
nuclei
nuclei.
number
that
are
time.
activity
is
nuclei
decay
the
decreases.
reaches
activity
of
is
approaches
nuclei
approaches
shape
radioactive
decaying
activity
graph
number
A
a
curves
sample
nuclei
of
number
rate
This
remaining
curve.
of
leads
The
decay
to
a
in
a
number
slows
curve
as
of
the
which
zero.
of
the
sample
proportional
will
to
have
the
exactly
number
the
same
of
nuclei
of
the
5.6.1).
Time
Half-life
Figure
5.6.1
A
decay
curve
showing
The
the
number
of
half-life
nuclei
remaining
of
time.
over
a
to
decay.
a
nuclide
The
is
the
half-life
of
time
a
it
takes
particular
for
one
nuclide
half
is
a
active
constant.
perod
As
the
the
activity
half-life
activity
170
of
nuclei
of
a
is
can
proportional
also
sample
be
to
to
defined
fall
to
the
as
half
number
the
of
its
of
length
nuclei
of
original
time
value.
remaining,
taken
for
the
T
able
5.6.1
Number
of
half-lives
Fraction
of
sample
0
remaining
1
1
1
2
EXAM
TIP
1
2
4
Y
ou
can
find
the
1
halflife
3
of
8
an
an
Figure
45
5.6.2
minutes.
measuring
means
same
is
the
that
as
shows
It
time
the
the
the
decay
important
for
time
time
half
taken
taken
curve
for
note
that
to
of
for
for
it
the
the
to
a
sample
the
remaining
activity
fall
from
with
half-life
sample
fall
300
from
to
a
half-life
can
to
600
be
decay.
to
of
found
300
or
by
iso to
pe
activ
ity
a
decay
num
ber
remai
ning
usin
g
of
eithe
r
cur ve
nucle
i
decay
cur ve
.
This
is
the
150.
Activity
45 minutes
45 minutes
45 minutes
600
300
150
75
0
50
100
150
Time/min
Figure
5.6.2
The
45
decrease
minutes.
every
Some
nuclides
indicates
that
example,
Some
For
45
have
the
nuclides
very
nuclei
have
activity
for
activity
a
radioactive
(and
number
sample
of
nuclei
with
a
half-life
remaining)
of
halves
minutes.
dubnium-261
example,
in
The
short
are
has
very
a
of
half-lives,
has
a
fractions
unstable
half-life
long
uranium-238
half-lives,
very
and
27
of
a
second.
very
This
quickly.
For
seconds
millions
half-life
of
decay
4.5
or
billions
billion
of
years.
years.
SUMMARY
1
KEY
The
The
for
half-life
the
of
activity
a
sample
of
that
of
a
radioisotope
sample
to
fall
to
is
half
the
of
time
the
taken
Half-lives
original
The
the
4
fermium-253
The
half-life
fifteen
can
vary
from
milliseconds
to
billions
of
years.
2
If
the
longer
the
half-life
the
lower
the
activity
(rate
of
decay)
of
fraction
sample
falls
3
a
What
activity.
2
isotope
POINTS
has
1
QUESTIONS
will
three
of
the
remain
days.
original
after
days?
activity
from
of
2000
an
isotope
counts
per
of
second
to
second
in
500
counts
per
radioisotope.
decay
process
is
independent
of
external
conditions.
half-life
one
of
the
day
what
is
the
sample?
171
5.7
Applications
of
radioisotopes
Although
LEARNING
also
At
the
should

end
be
explain
radioactive
of
this
able
how
topic
very
useful
can
medicine
and
Medical
uses
be
used
are
potentially
how
to
very
dangerous
they
are
archaeology.
of
radioisotopes
containing
radioisotopes
can
be
used
as
tracers
inside
industry
the
age
They
materials
can
injected
gathering
into
in
the
target
body
and
organs.
move
The
through
tracers
emit
the
gamma
be
radiation
carbon
are
of
bloodstream,
using
medicine
tracers
patients.
found
from
in
Compounds
organic
fields
radioactive
materials
describe
in
you
to:
Medical

materials
OUTCOMES
which
is
detected
outside
the
body
with
a
gamma
camera.
A
dating.
computer
as
produces
blockages
gamma
in
trace
blood
being
Technecium-99m
diagnostic
radiation
has
a
long
images
which
short
vessels
used
to
(Tc-99m)
medicine.
is
This
easily
half-life
from
and
the
can
be
detect
is
information
the
identified.
a
blocked
most
isotope
detectable
therefore
by
Figure
kidney
common
decays
by
not
problems
5.7.1
(Chart
tracer
releasing
gamma
does
and
in
shows
a
B).
used
in
gamma
cameras.
stay
such
the
Tc-99m
patient
also
for
a
time.
Radiotherapy
Radioactive
cancer
rays
normal
than
radiation.
radiation
Chart
recorder
A
Chart
recorder
emissions
However,
the
by
10
Figure
5.7.1
A
A
Chart
gamma
detected
recorder
trace
from
can
B
be
a
gas
Geiger
at
a
a
be
destroyed
high
tumour.
The
intensity
cancer
cause
by
the
beam
cells
cancers.
from
gamma
gamma
of
gamma
receive
a
high
dose
and,
hopefully,
die
off.
The
gamma
rays
may
be
and
civilian
out
the
applications
leaks
from
a
pipeline
it
can
be
difficult
to
fi nd
exact
pipe
body
during
diagnosis.
is
of
the
leak.
counter
A
can
radioactive
be
used
to
tracer
detect
can
the
be
added
radiation
to
the
leak
gas
even
if
and
the
underground.
outside
The
the
thickness
of
aluminium
foil
can
be
measured
with
a
beam
of
beta
medical
radiation.
too
thin
Smoke
source
If
the
the
foil
count
detectors
produces
the
air
fire
absorbs
current
is
in
too
rate
rely
from
a
is
thick
the
on
gap
the
detected.
then
increases
the
radiation
ionises
in
172
can
can
damage
Min
location
recorder
so
and
to
20
When
Chart
and
ionising
susceptible
cobalt-60.
Industrial
Min
highly
radiotherapy
directed
radiation
produced
20
be
more
B
of
10
are
cells
During
is
can
cells
and
This
(Figure
ionising
which
ions
the
the
off
an
of
drops.
radiation.
through
resulting
by
rate
If
the
foil
is
5.7.2).
effect
passes
created
sets
count
the
a
current
alpha
alarm.
small
is
An
air
alpha
gap,
detected.
particles
and
Smoke
the
fall
Radiocarbon
dating
Radioactive
Rollers
Any
organism
during
but
a
its
contains
lifetime.
small
carbon
Most
proportion
of
is
the
atoms
absorbed
carbon
carbon-14,
is
a
from
carbon-12,
beta
emitter.
the
a
source
atmosphere
stable
When
isotope,
carbon-14
Metal
decays
it
forms
a
stable
isotope,
14
nitrogen-14.
14
C
→
0
N
6
+
β
7
–1
Geiger
The
proportions
of
carbon-12
and
carbon-14
in
the
atmosphere
are
tube
constant,
rays
at
as
the
new
same
carbon-14
rate
that
is
produced
carbon-14
by
interaction
decays.
This
with
means
cosmic
that
all
living
Machinery
organisms
the
maintain
organism
dies
a
it
constant
no
longer
ratio
takes
of
in
carbon-14
new
to
carbon.
carbon-12.
The
Once
control
carbon-12
Figure
nuclei
are
stable
but
the
carbon-14
nuclei
continue
to
decay
and
5.7.2
A
beta
ratio
of
carbon-14
to
carbon-12
decreases
over
control
the
can
activity
ratio
can
measure
of
a
then
the
sample
be
used
of
to
ratio
of
carbon
find
the
two
taken
out
how
isotopes
from
long
by
the
remains.
organism
has
a
half-life
of
5700
years
and
so
This
the
which
died
5700
years
ago
would
have
remains
half
of
as
an
organism
that
died
today.
For
out
some
as
example,
2000
that
is
an
years
the
important
old.
plants
techniques
However,
used
can
religious
be
to
artefact
radiocarbon
make
used
with
years
ago.
it
died
originally
dating
only
uranium
to
on
the
the
find
the
to
Shroud
years
billions
of
ages
using
T
c-99m.
of
Why
a
2
A
would
sample
an
alpha
particle
emitter
not
be
suitable
taken
from
an
arrow
is
found
by
safety
in
place?
for
use
as
radiocarbon
EXAMPLE
ancient
found
to
piece
have
to
carbon-14
of
a
modern
Estimate
piece
wood
be
rocks
tracer?
of
What
to
Similar
QUESTIONS
medical
need
showed
ago.
is
1
diagnostic
carried
be
An
SUMMARY
the
are
T
urin
WORKED
formed
of
foil.
much
thought
700–800
of
that
precautions
Shroud
aluminium
an
out
carbon-14
or
ACTIVITY
procedures
organism
used
died.
Find
Carbon-14
be
thickness
measuring
biological
ago
can
the
time.
paper
Scientists
source
so
to
the
to
rollers
The
of
the
of
an
cotton
activity,
decay,
¼
cotton
age
of
cloth
of
due
that
sample.
the
ancient
cloth.
cloth
has
decayed
over
1
dating
to
have
an
activity
of
that
for
a
modern
piece
of
2
the
half-lives
and
so
is
2
×
5700
8
same
KEY
1
In
medicine
wood.
Estimate
radioactive
cancers
Radioactive
a
3
of
the
age
of
the
=11 400
arrow.
years
old.
POINTS
treat
2
type
material
Radioactive
organic
materials
or
materials
are
used
as
tracers
and
to
(radiotherapy).
detect
dating
can
flaws
be
in
used
to
measure
the
thickness
of
it.
techniques
can
be
used
to
find
the
age
of
materials.
173
5.8
The
release
nuclear
The
LEARNING
law
the
should
end
be
energy
conservation
of
energy
states
that
energy
cannot
be
OUTCOMES
created
At
of
of
of
this
able
topic
or
realised
you
given
to:
destroyed.
that
mass
Energy
was
must
equivalent
be
to
conserved.
energy
and
Albert
this
Einstein
relationship
was
by:
2
energy

calculate
the
energy
=
mass
×
speed
of
light
released
2
when
mass
nuclear
changes
in
or
a
describe
the
advantages
disadvantages
nuclear
associated
with
power.
Whenever
in
mass.
In
nuclear
to
energy
mass
and
this
a
change
means
(splitting)
of
these
mass
in
that
a
large
smaller
change
EXAMPLE
energy
mass
there
can
be
nucleus
nuclei
leads
to
is
a
is
an
associated
transformed
is
split
less
into
than
large
two
the
release
change
into
energy.
small
original
of
energy.
1
TIP
How
as
is
also
fission
WORKED
give
mass
there
This
The
nucleus
Mak
e
mc
and
nuclei.
EXAM
=
reaction
Converting

E
sure
adva
that
ntag
you
es
can
this
much
energy
well
1
U
+
92
disadv
anta
ges
released
during
the
nuclear
fission
shown
in
equation?
235
as
is
144
n
→
90
Ba
0
+
1
Kr
56
+
2
36
n
0
of
−25
nucle
ar

powe
r
.
mass
of
uranium-235
=
3.902996
×
10
kg
−25

mass
of
barium-144
=
2.389897
×
10
kg
−25

mass
of
krypton-90
=
1.493157
×
10
kg
−27

mass
of
Calculate
a
neutron
the
=
1.674927
difference
between
×
10
the
kg
starting
mass
and
the
end
mass.
Δm
=
mass
before
fission
−
mass
after
+
1.674927
fission
−25
Δm
=
(3.902996
×
10
−27
×
10
) kg
−25
−
(2.389897
+
2
×
10
−25
+
1.493157
×
10
−27
×
1.674927
×
10
) kg
−28
Δm
=
Now
3.1927
convert
×
10
this
kg
loss
of
2
E
=
mc
mass
to
energy.
−28
=
3.1927
×
10
8
kg
×
(3.00
×
10
−1
m s
2
)
−11
=
Although
there
very
large
Once
how
the
are
this
to
Figure
5.8.1
A
nuclear
energy
vast
of
10
of
mass
bomb.
enough
into
The
energy
than
any
seen
by
one
nuclei
energy
understood
convert
J
released
number
amount
was
×
in
could
provide
before.
decay
gram
began
The
conversion
to
nuclear
every
potentially
scientists
energy.
explosion
greater
174
the
a
nuclear
release
2.8734
of
an
first
a
to
of
be
is
very
matter
small
so
a
released.
develop
application
amount
explosion
small,
and
ideas
of
of
about
the
idea
matter
thousands
of
was
would
times
Nuclear
fission
power
stations
WORKED
Nuclear
fission
power
stations
use
the
thermal
energy
released
water
into
steam
which
drives
turbines.
These
are
then
used
much
generators
which
produce
During
fission
this
is
caused
process
by
several
a
neutron
other
colliding
neutrons
are
with
a
large
released
and
nucleus.
these
used
to
neutrons.
split
This
other
nuclei,
process
is
releasing
called
1
would
gram
a
more
chain
energy
reaction
and
(Figure
yet
completely
of
be
matter
converted
into
energy?
can
2
E
be
if
electricity.
were
Induced
energy
to
released
drive
2
to
How
heat
EXAMPLE
=
mc
=
0.001 kg
more
×
(3.00
×
5.8.2).
8
−1
10
m s
2
)
13
Key
components

Fuel:
Uranium

Moderators:
or
of
a
fission
plutonium
is
=
reactor
used
inside
canisters
called
fuel
rods
can
be
This
9.00
is
slow
down
the
neutrons
so
that
they
by
chemical
absorbed

Coolant:
and
by
This
carries
There
are
national
T
able
the
fuel
removes
it
to
a
for
governments
cause
the
heat
arguments
5.8.1
and
energy
20 000
than
that
tonnes
of
explosives.
fission.
thermal
and
energy
for
against
the
consider
and
against
For
from
the
reactor
core
use
(T
able
the
use
of
nuclear
power,
which
5.8.1).
of
nuclear
power
Against

Running

Only
a
costs
small
are
low.
amount

of
Commissioning
waste
and
produced.

J
exchanger.
must
Arguments
10
more
released
These
×
Large
decommissioning
(dismantling)
supplies
of
nuclear
fuel

Nuclear
available.
(building)
costs
waste
radioactive
are
Figure
high.
5.8.2
A
chain
reaction
contains
isotopes.
ACTIVITY

No
so
carbon
no
dioxide
is
contribution
produced
to

Waste

Accidents
global
products
nuclear
can
be
used
in
weapons.

warming.
such
as
occurred
Research
the
advantages
disadvantages
Chernobyl
and
Fukushima
large
a
fusion
in
form
energy
larger
possible
been
at
is
also
ones.
very
This
high
reproduced
released
process
when
very
occurs
temperatures
QUESTIONS
1
What
nuclear
2
How
much
2
H
+
chain
energy
3
1
is
→
in
and
small
the
nuclei
cores
pressures,
of
combine
stars
which
and
have
is
how
only
not
Find
arguing
construction
station
out
what
up
yet
long
the
on
your
went
and
of
island.
it
wrong
Fukushima
will
take
to
contaminated
in
and
clear
land.
in
this
fusion
1
process?
Mass
can
in
be
converted
nuclear
into
reactions
n
0
according
=
3.344494
×
10
to
the
relationship
2
−25
hydrogen-2
POINTS
energy
+
2
of
against
Chernobyl
to
1
He
1
(mass
report
reaction?
released
4
H
or
power
KEY
a
a
sustainably.
SUMMARY
is
Write
stars

Nuclear
nuclear
areas.
for
Nuclear
of
can
energy.
contaminate
and
in
kg,
mass
E
of
=
mc
−25
hydrogen-3
=
5.008267
×
10
kg,
mass
of
helium-4
=
2
Nuclear
power
can
provide
−25
6.646476
×
10
kg)
large
3
A
sugar
cube
equivalent
to
has
a
this
mass?
mass
of
12 g.
How
much
energy
is
amounts
energy
and
but
of
there
useful
are
risks
disadvantages.
175
Section
Section
1
The
5:
Practice
activity
measured
the
a
5
of
a
over
Practice
exam
sample
a
of
radon-220
time
as
is
3
shown
in
a
During
to
table.
Plot
of
activity
against
time
for
the

sample.
b
Identify
Most
the
anomalous
result.

A
Use
the
graph
to
find
the
half-life
Geiger–Marsden
the
structure
results
of
the
through
small
were
c
the
explore
following
graph
questions
questions
of
period
exam
were
alpha
the
gold
by
experiment
the
atom,
the
noted:
particles
passed
directly
foil.
percentage
deflected
of
of
the
angles
alpha
particles
between
0
and
of
90
degrees.
radon-220.

d
Predict
the
time
it
would
take
for
A
few
alpha
angles
activity
to
fall
to
10
counts
per
particles
were
deflected
by
the
greater
than
90
degrees.
second.
a
For
each
describe
the
conclusions
about
−1
Time/s
Activity/s
the
0
500
20
389
structure
made
b
Why
of
based
on
was
gold
was
the
the
atom
this
used
that
can
be
evidence.
as
the
material
for
the
foil?
40
302
60
235
c
Why
evacuated
80
182
100
150
4
Electrons
or
120
110
140
86
160
67
180
200
What
of
40
iii
Calcium
iv
Neon
table
different
Number
hydrogen-2
showing
Z
hydrogen-3
Which
two
of
similar
the
elements
chemical
176
nitrogen-14
d
chlorine-35
will
Nucleon
A
Number
of
neutrons,
an
levels
N
Number
of
electrons
of
have
properties?
Electron
configuration
1
3
(tritium)
c
energy
the
number,
in
the
elements?
(deuterium)
b
in
nuclides.
of
out
configuration
following
Sodium
this
found
electron
the
ii
protons,
a
the
of
52
the
Nuclide
are
Magnesium
complete
components
atoms
i
most
and
is
atoms
b
Copy
carried
shells.
a
2
in
experiment
chamber?
7
2,8,7
the
5
Which
of
the
isotopes
listed
in
the
table:
8
This
graph
argon-39
a
are
isotopes
of
the
same
b
contain
the
same
number
of
nucleons?
c
contain
the
same
number
of
neutrons?
d
contain
the
same
number
of
protons?
shows
and
a
the
activity
sample
of
of
a
sample
of
silver-108.
element?
a
Determine
the
half-life
of
argon-39.
b
Determine
the
half-life
of
silver-108.
c
Which
sample
has
the
higher
initial
activity?
35
40
36
Cl
Ar
17
Ar
18
38
18
36
Ar
S
18
Activity/Bq
37
5000
Cl
16
17
4500
Silver
35
36
S
Cl
16
4000
40
Argon
Ar
17
3500
18
3000
2500
223
6
The
nuclide
thorium-223
(
Th)
2000
undergoes
90
1500
nuclear
decay
isotope
of
by
alpha
emission
to
form
an
1000
radium
500
(Ra).
0
a
Which
nucleons
are
present
in
an
0
alpha
100
200
300
400
particle?
b
500
600
700
800
900
1000
Time/year
Write
a
alpha
decay.
decay
equation
representing
the
9
Write
decay
equations
for
the
following:
107
a
The
alpha
decay
of
(
tellurium-107
Te)
52
7
This
graph
shows
the
relationship
between
into
the
proton
number
(atomic
number)
and
an
isotope
of
tin
(Sn).
of
potassium-40
the
40
neutron
number
for
all
of
the
stable
b
nuclides.
The
Describe
the
relationship
for
nuclides
of
decay
(
K)
into
19
an
a
beta
isotope
of
calcium
(Ca).
a
90
low
b
proton
Describe
higher
N
number
the
of
<
relationship
proton
(Number
(Z
number
(Z
c
20).
for
>
The
gamma
decay
of
(
strontium-90
Sr).
38
nuclides
of
a
10
20).
A
single
all
of
a
neutrons)
nuclear
the
Write
idea
on
b
a
of
few
reactor
could
requirements
paragraphs
building
a
for
provide
Trinidad.
supporting
nuclear
power
the
station
Trinidad.
Write
of
fission
electricity
a
few
building
paragraphs
the
power
opposing
the
idea
station.
126
11
Nuclear
the
radiation
thickness
of
manufacture.
can
be
used
materials
Describe
to
during
how
the
measure
their
thickness
82
Protons
=
neutrons
of
a
metal
radiation
foil
so
can
that
a
be
measured
constant
using
thickness
beta
can
be
50
maintained
during
the
manufacturing
process.
28
14
6
6
14
28
50
Z
82
(Number
of
protons)
177
Glossary
A
C
Absolute
zero
The
temperature
(0 K
temperature
all
lowest
or
of
possible
−273 °C).
the
At
thermal
D
Celsius
this
scale
temperature
energy
has
of
water
of
water.
A
centigrade
with
and
0 °C
100 °C
at
at
scale
the
the
for
Decay
freezing
boiling
point
constant
decaying
per
removed
from
a
material.
a
Absorb
an
To
take
increase
in
in
radiation.
This
results
in
temperature.
Centre
of
the
of
gravity
weight
of
The
an
point
object
at
which
seems
to
all
velocity.
The
The
unit
rate
of
of
change
acceleration
of
is
Chain
metres
reaction
neutrons
are
During
released.
nuclear
second
squared
transfer
a
=
Δv/t
cause
further
fissions
These
of
fission
neutrons
nuclei
and
The
material.
Accuracy
An
accurate
measurement
set
which
of
is
close
to
the
measurements
of
true
a
value.
quantity
neutrons
causing
an
energy
if
their
mean
is
close
to
do
not
but
share
which
them.
mass
per
=
unit
mass
volume
÷
of
a
volume.
in
variable
response
A
to
variable
an
that
independent
during
an
experiment
or
release.
A
investigation.
can
the
that
current
between
Density
be
Charles’
law
For
a
fixed
mass
of
gas
the
Destructive
accurate
a
increasing
variable
of
nucleus
can
is
rate
one
more
a
release
changes
even
circuits
through
energy
Dependent
).
(m s
of
act.
−2
per
T
wo
connection
Density
Acceleration
chance
point
Decoupled
been
The
second.
true
volume
is
proportional
to
the
two
value.
temperature
if
the
pressure
interference
When
absolute
is
waves
meet
out
of
phase
(e.g.
a
kept
crest
meeting
a
trough),
the
waves
constant.
Activity
sample
(the
The
is
activity
the
number
rate
of
of
of
a
radioactive
decay
nuclei
of
which
the
superimpose
nuclei
decay
each
Compression
pressure
in
a
An
area
sound
of
higher
air
and
displacement
partly
out
at
cancel
that
each
other’s
point.
wave.
Diffraction
The
spreading
of
a
wave
second).
Conduction
Alpha
particle
consisting
neutrons
of
(a
A
two
radioactive
protons
helium
emission
and
energy
two
pass
nucleus).
also
through
energy
radiation
The
emission
of
transfer
a
via
energy
of
material
though
conduct
transfer
Alpha
The
thermal
when
vibrations.
free
electrons
more
when
atoms
an
Metals
which
The
and
two
emitted
neutrons
particles
from
form
a
a
nucleus.
helium
Conductor
electricity
through
depends
can
quickly.
meter
used
to
greatest
current
(in
ampere,
measure
A)
in
the
A
(or
material
thermal
that
The
maximum
a
circuit.
waves
to
flow
Diffuse
surface
distance
of
meet
crest),
interference
from
its
rest
position
in
a
of
incidence
The
angle
incident
ray
and
the
When
phase
waves
the
of
reflection
reflected
ray
and
distance
Average
speed
The
the
The
measured
speed
=
gap;
when
the
the
these
are
(e.g.
size.
a
crest
superimpose
reflection
which
travel
in
is
Reflection
not
smooth.
different
from
The
directions
a
reflected
can
be
and
so
no
seen.
meeting
and
amplitude
at
that
Diminished
point.
when
An
image
reduced
to
original
compared
the
in
size
object.
force
objects
A
are
force
in
which
direct
acts
contact
when
with
each
Dispersion
frequencies
The
of
spreading
light
of
caused
different
by
angle
difference
White
between
variable
A
variable
that
in
light
their
can
speeds
be
in
a
the
dispersed
medium.
by
a
prism.
must
normal.
rate
over
occurs
between
the
normal.
be
Average
of
between
Control
the
size
two
other.
Angle
the
past
diffraction
relationship
and
or
vibration.
two
an
of
gap
a
Contact
Angle
in
the
increase
particle
the
a
allows
energy)
it.
Constructive
a
Amplitude
amount
diffraction
same
image
electric
on
wavelength
rays
A
The
through
two
nucleus.
Ammeter
passes
edge.
the
protons
it
of
a
change
period
distance
of
travelled
of
time.
÷
time
or
kept
constant
investigation
relationship
during
in
an
order
between
independent
variable
Convection
current
the
to
experiment
to
allow
dependent
be
Displacement
the
origin
and
determined.
(starting
direction.
The
distance
point)
in
a
Displacement
is
from
an
particular
measured
in
metres.
taken.
of
B
particles
transfer
fluid.
Background
radiation
The
A
of
the
surroundings.
This
rocks,
radon
gas
and
radiation
A
of
a
from
cosmic
radioactive
fast-moving
the
A
a
gas
whole
body
temperature
of
a
in
law
is
For
a
fixed
inversely
a
178
if
the
a
particular
of
a
fluid
as
it
heats
graph
instant.
graph
A
graph
up
the
changes
in
displacement
The
line
on
a
temperature–
an
object
gradient
of
over
a
a
period
section
of
of
the
time.
graph
The
is
that
shows
how
a
substance
speed
of
the
object
at
that
the
time.
down.
angle
The
angle
of
incidence
at
To
spread
surroundings.
out
Thermal
into
the
energy
an
incident
ray
will
be
refracted
into
the
surroundings
where
dissipates
it
cannot
be
throughout
at
a
to
mass
Current
of
gas
proportional
is
the
boundary.
used
to
do
any
additional
work.
specific
point).
temperature
at
A
particles
liquid
to
kept
The
an
rate
of
object.
flow
The
of
charge
current
is
Distance
measured
the
amperes
where
1 A
the
of
volume
wave
the
electron
in
pressure
density
curve
graph
through
Boyle’s
a
of
emission
from
liquid
boiling
in
graph
positions
the
Dissipate
state
happens
of
(the
the
by
of
parallel
the
caused
nucleus.
change
which
is
the
contracts.
which
into
throughout
current
representing
rays.
Critical
Boiling
Displacement–position
the
showing
cools
ejected
energy
by
Displacement–time
time
consisting
movement
caused
radiation
Cooling
Beta
thermal
The
fluid
radioactivity
includes
or
from
a
convection
changes
in
within
constant.
charge
per
second.
is
the
transfer
of
1 C
point.
The
How
SI
far
unit
an
of
object
distance
moves
is
the
from
a
metre.
Glossary
Focal
E
length
where
Echo
The
reflection
of
a
sound
The
parallel
distance
rays
from
parallel
to
a
the
lens
to
I
optical
wave.
Impulse
axis
will
be
brought
together
caused
Efficiency
A
measure
of
how
effective
a
lens)
or
seem
to
come
from
by
is
energy
at
transferring
usefully.
or
Efficiency
useful
energy
÷
total
energy
in.
Efficiency
can
as
a
decimal
or
as
a
plane
The
plane,
perpendicular
to
0.4
or
40%
surface
axis,
were
the
principal
focus
ray
such
Free
efficient).
electrons
which
limit
The
point
beyond
which
will
no
longer
return
the
Metals
to
its
outer
form
when
the
force
on
the
electrons
a
structure
object.
The
as
a
ray
which
strikes
a
mirror.
These
are
free
free
to
variable
A
variable
which
is
in
in
an
experiment
to
see
how
that
move
change
atoms.
electrons
affects
the
dependent
variable.
are
original
responsible
length
an
lies.
a
between
spring
on
percentage
changed
Elastic
momentum
Ft
Independent
(e.g.
in
acting
a
be
lens
expressed
=
Incident
Focal
out
change
force
lens).
transforming
=
a
(diverging
Impulse
device
The
(converging
spring
for
electrical
conduction
and
Induce
To
transfer
magnetic
or
electrical
is
most
thermal
conduction
in
metals.
properties
without
physical
contact.
removed.
Frequency
Electromagnetic
Related
to
electric
pass
magnetic
a
point
complete
second.
The
waves
unit
Induction
of
The
electromotive
production
force
(a
of
an
voltage)
in
a
wire
by
−1
Electromagnetic
an
many
each
fields.
frequency
by
How
and
relay
Switch
operated
is
s
which
is
also
called
hertz
a
magnetic
field
moving
relative
to
it.
(Hz).
Inertia
The
change
its
reluctance
of
an
object
to
electromagnet.
Friction
Electromagnetic
spectrum
waves
properties.
with
similar
A
set
two
of
amount
of
coulomb
battery.
of
A
Electrons
=
as
it
to
The
which
each
passes
found
The
releasing
through
acting
opposes
between
movement.
planets,
joining
energy.
releases
of
small
Fusion
energy
is
in
the
process
charged
energy
particle.
levels
that
of
radiation
electromagnetic
High
to
Large
objects,
amounts
speed
up
released
thermometer
measures
the
the
infra-red
of
or
to
from
a
object
determine
at
a
A
intensity
radiation
Instantaneous
frequency
radiation
large
difficult
object
Gamma
or
have
Infra-red
Sun.
G
in
are
motion.
such
inertia
slow
as
and
down.
nuclei
the
a
E/Q
negatively
are
which
force
so
(e.m.f.)
provided
charge
e.m.f.
Electron
force
energy
contact
surfaces
Fusion
Electromotive
The
the
speed
particular
thermometer
and
frequency
emitted
by
an
temperature.
The
speed
moment.
of
an
Measured
−1
shells
can
around
be
the
ejected
nucleus
from
the
of
an
atom
nucleus
or
Gas
beta
in
nucleus.
metres
per
second
equation
A
relationship
Insulator
between
A
poor
Electrostatic
precipitation
Using
a
of
pressure,
a
fixed
volume
amount
and
metal
grid
to
induce
charge
onto
pV/T
=
heat
or
of
an
ideal
gas.
smoke
from
particles
the
Emit
To
air
.
that
Used
give
radiation
so
or
in
out
they
can
power
be
station
radiation,
e.g.
Gas
thermometer
A
uses
the
a
Evaporation
infra-red
pressure
from
to
do
work.
energy
A
process
the
where
surface
of
a
energetic
the
particles
average
escape
interference
of
gas
to
indicate
patterns
formed
energy
of
potential
associated
a
are
experiment
with
gravitational
energy
an
object
field.
The
same
liquid.
This
reduces
change
it
is
in
Inverted
it
is
as
An
upside
potential
energy
can
be
Clear
destructive
interference
the
in
Young’s
overlapping
two-slit
waves
have
image
is
said
to
be
inverted
if
down.
found
Ionisation
and
the
relationship
ΔE
=
so
particles
temperature
from
Gravity
two
The
objects
force
due
of
to
attraction
their
The
removal
of
an
electron
mgΔh
an
atom
creating
an
ion.
between
Atoms
of
the
same
element
mass.
(having
the
waves.
The
when
The
first
the
the
pattern
and
frequency.
Isotopes
the
The
constructive
particles
liquid.
from
reduce
of
temperature.
gravitational
most
which
the
capacity
the
chimneys.
inside
escape
thermometer
light.
The
by
removed
Gravitational
Energy
pattern
constant.
formed
the
same
number
of
protons)
that
liquid.
Greenhouse
Extension
spring
(or
applied
The
other
to
it.
spring
is
increase
object)
For
proportional
the
of
electricity.
temperature
Interference
charged
of
conductor
decay.
the
in
).
(m s
during
to
a
in
spring
the
size
extended
length
when
the
of
a
of
a
force
thermal
is
extension
the
beyond
force
the
to
is
effect
energy
greenhouse
radiation
by
the
gases
emitted
The
by
capture
atmosphere
reflecting
the
have
of
numbers
of
neutrons.
due
infra-red
K
Earth.
Kelvin
unless
limit
different
on
of
the
scale
A
temperature
properties
of
ideal
scale
gases
based
and
the
H
energy
proportionality.
Half-life
The
time
taken
for
the
activity
of
of
Kinetic
a
radioactive
sample
to
fall
to
half
of
with
initial
value.
Hard
magnetic
energy
the
movement
1
E
The
splitting
accompanied
by
a
of
a
release
nucleus
of
material
which
be
induced
using
mv
2
magnetic
properties
theory
Heat
A
liquid
or
gas.
The
particles
are
capacity
move
to
flow.
past
each
other
allowing
the
The
amount
of
energy
The
of
kinetic
solids,
particle
theory
is
liquids
model
used
and
of
the
to
gases.
explain
the
able
which
to
The
well.
neutrons.
behaviour
Fluid
associated
object.
retains
Kinetic
can
an
energy.
its
Fission
energy
of
2
=
k
A
The
its
F
Fission
particles.
can
be
stored
in
a
body
per
degree
changes
of
state
and
pressures
within
fluid
kelvin
(or
Celsius).
gases
and
liquids.
179
Glossary
Momentum
L
an
Laser
A
device
which
produces
a
object
as
intense
(light
with
beam
a
of
single
monochromatic
heat
change
the
The
the
property
of
required
P
relationship
Parallel
=
mass
×
effect
inside
A
a
current-carrying
magnetic
field
wire
are
the
parallel
Pascal
a
force.
that
This
is
the
current
have
can
junctions
diverge
or
at
merge
circuits.
will
to
experience
Circuits
velocity.
which
Motor
wavelength).
energy
by
light
placed
Latent
movement
narrow
momentum
and
The
defined
motor
(Pa)
A
unit
of
pressure.
The
pascal
effect.
−2
to
a
liquid
state
or
of
an
liquid
to
object
a
(from
a
solid
is
heat
of
fusion
The
Penumbra
energy
to
melt
a
substance.
The
of
energy
is
released
when
electric
to
of
vaporisation
vaporise
a
liquid
The
a
during
an
This
carry
charge
field
which
will
affect
causes
Period
The
oscillation
other
time
of
a
it
takes
system.
for
It
is
one
complete
measured
in
liquid
energy
is
to
a
gas).
released
The
when
same
the
An
back
into
a
uncharged
particle
found
in
Photon
A
packet
of
energy
carried
by
it
nucleus
of
an
atom.
light.
The
higher
more
energy
the
frequency
of
light
the
amount
each
photon
carries.
vapour
Neutron
condenses
seconds.
energy
(change
the
of
Electrons
charge.
objects.
Neutron
from
shadow
solidifies.
heat
required
charged
electric
charged
Latent
partial
the
an
substance
The
same
negative
quantity
N m
eclipse.
Negatively
required
to
solid).
N
Latent
equivalent
number
The
number
of
liquid.
neutrons
within
a
particular
Pitch
nucleus.
A
high
frequency
sound
has
high
pitch.
Laterally
displaced
When
a
ray
passes
Newton
through
a
rectangular
block
of
are
material
it
is
refracted
on
(N)
entry
vector
the
it
ray
but
leaves
the
travelling
shifted
block.
in
the
(displaced)
This
unit
quantities.
of
force.
This
Forces
means
that
the
and
direction
when
The
transparent
results
original
which
they
act
is
significant.
Non-renewable
from
will
its
eventually
An
run
energy
out
or
source
become
which
path.
Lattice
vibration
positive
Potential
volts.
cause
particles
in
a
solid
The
vibrations
which
cause
of
Normal
the
A
line
at
right
angles
to
surface.
thermal
Angles
refraction
are
of
all
incidence,
measured
reflection
relative
to
dependent
resistor
which
depending
to.
In
but
on
bright
in
dark
resistor
changes
the
light
light,
conditions
it
have
they
carries
difference
A
by
a
unit
potential
1
(p.d.)
charge,
difference
coulomb
of
The
of
charge
energy
measured
to
1
volt
in
will
joule
of
transfer
energy.
Power
The
measured
rate
in
of
watts
transfer
(W).
P
of
=
energy
E/t
(LDR)
Nuclear
resistance
level
LDRs
proton
and
this
normal.
A
A
the
1
conduction.
Light
charged
charge.
transferred
very
scarce.
original
Positively
in
direction
sideways
in
is
exposed
low
have
resistance
very
Related
atom.
Nuclear
nuclei
are
to
the
energy
split
nucleus
is
(fission)
of
released
or
Precision
an
when
merged
(fusion).
The
degree
to
measurements
agree.
A
measurements
will
be
all
which
set
of
very
repeated
precise
similar.
high
Nucleon
A
particle
found
in
the
nucleus.
Pressure
law
For
a
fixed
mass
of
gas
the
resistances.
The
Limit
of
which
a
proportionality
spring
can
be
The
limit
stretched
possible
remaining
proportional
to
acting
on
the
spring
(still
protons
and
pressure
is
absolute
directly
temperature
if
the
to
the
volume
is
kept
number
The
total
number
of
the
and
neutrons
in
a
Primary
nucleus.
cell
A
cell
which
cannot
be
obeying
recharged.
Hooke’s
proportional
constant.
protons
force
are
the
Nucleon
extension
nucleons
neutrons.
to
with
two
law).
Nucleus
The
central
part
of
an
atom.
Zinc–carbon
cells
are
primary
The
cells.
nucleus
Linear
magnification
A
comparison
size
of
the
image
to
the
size
of
image
Linear
÷
magnification
height
of
=
the
volume
height
all
A
object.
wave
Nuclide
motion
where
of
the
particles
are
small
amount
of
of
the
the
atom
but
Principal
contains
mass.
centre
the
lens.
A
particular
carbon-14
type
is
a
of
nucleus.
different
direction
of
wave
motion.
parallel
Sound
Principal
rays
nitrogen-14.
that
is
M
A
ray
centre
which
focus
enter
principal
For
a
nearby
magnetic
magnetic
axis
The
passes
central
through
point
the
of
a
lens.
the
rays
point
seem
exerts
a
materials
force
by
does
not
change
a
Origin
or
turning
measured
in
N m.
is
as
the
defined
perpendicular
the
The
starting
central
point
point
in
an
of
a
movement
in
(pl.
foci)
The
converging
are
through
point
lens
brought
lens
The
effect
of
moment
force
distance
a
of
multiplied
to
the
force
a
by
pivot.
force
the
Oscillation
a
point.
Most
sinusoidal.
the
A
regular
to
at
which
parallel
together
to
by
the
principal
the
focus
pattern
of
object
a
sine
the
original
parallel
through.
of
moments
to
the
or
the
For
an
clockwise
object
to
anticlockwise
moment
is
moment.
oscillation.
movement
oscillations
The
which
pass
equilibrium,
equal
studied
particle
wave.
around
a
are
direction
moves
in
wave.
ripples
light
a
180
runs
perpendicular
optical
be
field.
The
which
and
path.
on
producing
from
to
Propagation
Moment
a
diverging
Principle
centre
magnet
line
O
wave.
is
A
A
lens
a
Optical
Magnet
a
to
lens.
longitudinal
of
For
nuclide
the
the
axis
the
the
to
oscillations
very
of
example,
Longitudinal
a
the
nearly
object.
only
of
of
the
occupies
The
of
on
rays
lamp.
a
The
wave
spreading
is
said
to
propagation.
pond
For
propagate
propagate
in
all
of
energy
travel
in
example,
in
a
circle
directions
by
the
the
and
from
Glossary
Proton
in
the
A
positively
nucleus
of
charged
an
particle
found
atom.
Specific
energy
of
Proton
number
The
number
of
the
nucleus
of
an
capacity
one
to
kilogram
raise
of
a
The
the
amount
of
Umbra
temperature
specific
material
during
The
an
in
complete
darkness
Unit
A
system
of
measurements
of
kelvin.
atom.
quantities.
Specific
to
region
eclipse.
by
protons
one
in
heat
required
latent
change
the
heat
state
The
of
energy
1 kg
of
a
required
is
material.
the
For
metre.
example,
Scientists
International
(SI)
of
the
use
unit
the
for
length
Système
Units.
R
The
specific
latent
heat
of
fusion
is
the
Unstable
Rarefaction
An
area
of
lower
pressure
in
energy
required
to
change
the
state
of
sound
wave.
of
the
The
Real
image
An
image
which
can
specific
onto
a
screen.
Rays
of
from
latent
a
solid
heat
of
into
a
unstable
equilibrium
An
if,
object
when
it
is
is
liquid.
vaporisation
disturbed,
it
falls
Upthrust
The
over.
is
be
the
projected
material
equilibrium
1 kg
in
a
light
energy
required
to
change
the
state
force
acting
on
an
object
pass
−1
from
through
a
real
liquid
to
a
gas.
Unit
is
J Kg
(or
submerged
or
floating
on
the
surface
of
image.
−1
J g °C
Rectification
The
conversion
of
).
an
current
into
direct
liquid.
weight
Spring
alternating
a
constant
The
force
required
If
the
of
the
upthrust
object
it
is
less
will
than
the
sink.
to
current.
−1
extend
Reflected
ray
The
ray
which
leaves
a
or
other
reflecting
index
The
of
light
in
a
vacuum
of
light
in
a
material.
ratio
(or
of
air)
the
to
speed
the
position
The
larger
the
is
N m
An
object
is
in
stable
slower
light
if
it
after
returns
being
to
the
Van
original
disturbed
de
device
(pushed).
form
A
numbering
format
A
travels
large
or
small
numbers
by
produce
In
standard
(VdG)
generator
generate
VdG
charges
generator
can
A
by
differences
large
generate
enough
to
scientists
in
engineers.
to
used
potential
form
large
sparks.
numbers
material.
b
are
Regular
reflection
The
reflection
from
a
represented
where
a
is
a
in
the
number
form
a
×
between
10
1
Vector
,
and
flat
produces
a
surface
clear
Renewable
An
such
as
a
mirror
which
and
is
image.
energy
source
b
is
used
an
to
integer.
For
represent
example,
3.4
×
10
an
inexhaustible
inexhaustible)
which
(or
force,
displacement
graph
the
velocity
a
Thermal
current.
R
=
Resolution
opposition
to
an
conductivity
material
The
rate
at
can
conduction.
A
conductivity
will
The
smallest
increment
can
detect.
the
The
be
resolution
of
a
ruler
resolution
of
a
referred
heat
energy
or
internal
with
energy)
the
is
particles
The
sum
of
the
or
an
object.
As
forces
within
direction
of
the
directions
(e.g.
forces
must
forces
must
be
acting
be
subtracted
in
a
thermistor
each
other).
or
the
area
distance
below
the
line
The
the
image
rays
of
of
light
an
object
appear
A
virtual
image
cannot
be
to
projected
a
screen
pass
as
the
rays
through
of
the
light
never
image.
A
meter
difference
used
(in
to
measure
volts,
V)
the
between
points
in
a
circuit.
The
voltmeter
must
temperature.
be
Transformation
of
the
resistor.
two
form
by
changes
taken
the
gradient)
image
potential
of
opposite
from
the
(shown
Voltmeter
Temperature-sensitive
resistance
with
account
The
acceleration
material.
vectors
The
the
an
forces
are
find
object
x-axis).
and
onto
the
to
the
the
movement
thermometer
of
used
(on
displaying
an
graph).
actually
force
by
which
come.
associated
time
of
to
be
Thermistor
on
the
from
may
be
graph
thermal
Virtual
(sometimes
of
A
y-axis)
quickly.
a
object
into
high
energy
0.5 °C.
Resultant
acting
with
transfer
For
arrangement
may
material
energy
velocity.
which
of
instrument
and
include
by
V/I
energy
1 mm.
energy
travelled
as
example,
thermal
electric
Thermal
measuring
transfers
(on
period
(shown
The
magnitude
vectors
and
the
graph
a
Resistance
with
example,
Velocity–time
over
effectively
supply.
quantity
For
34 000.
T
has
A
direction.
10
4
smooth,
the
Graaff
used
friction.
speed
and
the
Unit
the
for
index
metre.
equilibrium
Standard
refractive
1
surface.
equilibrium
Refractive
by
V
Stable
mirror
spring
a
energy
energy
can
energy
into
be
A
change
into
from
another.
transformed
For
one
placed
have
very
in
parallel
high
in
the
circuit
and
must
resistance.
example,
from
electrical
W
S
Scalar
A
quantity
magnitude.
include
For
mass
which
example,
and
only
Transformer
has
scalar
quantities
to
change
supply.
energy.
the
Secondary
cell
A
cell
which
can
A
A
lead–acid
cell
is
a
the
voltage
while
the
oscillations
A
material
which
certain
a
lamp.
which
of
an
is
alternating
transformer
a
pulse
Wave
train
other
in
an
electrical
placed
after
each
A
wave
are
magnetic
magnetic
A
that
loses
its
of
wave
The
propagates.
For
on
of
points
on
motion
where
perpendicular
to
the
the
crest
example,
a
a
ripple
all
wave
on
a
of
as
the
it
points
pond.
the
The
peaks
distance
U
the
symbol
is
λ
(or
between
troughs)
measured
in
in
a
wave.
metres
and
has
(lambda).
circuit.
material
properties
series
propagation.
Ultrasound
Soft
continuous
Wavefront
successive
one
oscillation.
transformer
conditions.
Components
A
Wavelength
of
single
voltage.
Wavelength
Series
A
pulses.
increases
step-down
Wave
used
will
direction
in
voltage
step-up
Transverse
conduct
device
by
secondary
cell.
Semiconductor
A
energy
be
reduces
recharged.
light
easily.
the
range
used
in
of
High-frequency
human
depth
sound
hearing.
measurement
above
Ultrasound
and
is
Work
The
measured
transfer
in
joules
of
energy.
Work
is
(J).
pre-natal
scanning.
181
Index
Key
terms
listed
in
are
the
in
bold
and
are
also
causal
cells
glossary
relationships
120–1,
photovoltaic
A
Celsius
absolute
a.c.
see
zero
alternating
acceleration
in
second
accuracy
acid
rain
170,
100,
see
24–5
171
in
also
68,
160,
to
d.c.
of
transformers
122
ampere
112
gates
132
78,
98,
99
of
incidence
of
reflection
results
principle
atmosphere
45,
84,
88
84,
88
47
69
163
160–2
speed
17,
167,
41
175
114,
circuit
diagrams
motor
164,
165
125
current
of
energy
35,
41
of
circuits
d.c.
decay
decay
138–41
in
in
thermal
124–5
emission
circuit
70,
71
45,
76,
138,
diagrams,
diffuse
diodes
141
direct
60
112,
66–7,
6,
9
interference
96,
current
97,
100
116–17
100
84–5
images
91,
92–3
136–7
(d.c.)
motors
130,
136–7
154
86,
displacement
72
37
3
reflection
dispersion
113
2,
124–5,
d.c.
168–71
energy
46–7
circuit
diminished
98
170
166,
variables
units
diffraction
116–17
54
170
geothermal
3,
173
current
radioactive
destructive
86
radiation
electrical
149
150–1
characteristics
169,
dependent
28–30
conduction
22
direct
derived
condensation
134
148,
effect
constant
and
123
momentum
waves
motor
curves
decay,
122–7
116–17,
compression
fuses
wires
radiocarbon
see
density
light
148–9
150–1
of
current-voltage
dating,
36
and
152–3
from
D
116–17
112–13
resistance
effect
ratings
the
124–5
123
134
126–7
in
current
127
122
current-carrying
116–19
analysis
field
measuring
and
potential
limit
current
magnetic
118
118–19
circuits
characteristics
induced
56
breakers
112–13,
resistors
60–5
112,
law
circuits
I-V
110–11
circuit
and
162,
in
109
carriers
computers
106,
16,
radiation
components,
46,
air
number
average
lightning
circuits
115
88–9
112–13
complex
112,
nuclear
97,
colours
8
Archimedes’
54,
in
collisions,
139
angle
atoms
circuits
coal
angle
also
in
logic
156–7
state
symbols
138,
anomalous
166
130–1
154–5
change
ammeters
amplitude
164–5,
136–7
153,
electricity
(A)
of
106–7,
chemical
(a.c.)
37,
gravity
charge
angle
current
reactions
Charles’
69
current
generation
mains
69
critical
51
change
on
atmosphere
particles
atomic
27
scale
of
charge
converting
see
chain
111
alternating
AND
current
26,
conditioning
alpha
centre
5
currents
air
23,
law
56
36
activity
air
51,
6
130
87
10,
22
B
conductors
background
radiation
47,
112
122–3,
units
of
120–1,
particles
equivalence
164–5,
systems
waves
dissipation
model
174
of
momentum
28–9
interference
97,
distance
100
diverging
forces
lens
12
waves
10,
energy
22,
35,
25
lenses
formula
90,
92–3
95
76
161
E
control
boiling
60,
Boyle’s
law
variables
6
61
Earth
convection
currents
68–9,
45,
73,
eclipses
current
earth
lenses
90–1,
wires
vision
132–3,
135
94–5
echoes
in
82–3
112
47
converging
146–7
72
56
conventional
buoyancy
100
93
C
eclipses
cooling
callipers
82–3
70–3
4
eddy
convection
cameras
83,
95,
currents
in
currents
and
evaporation
and
dioxide
36,
latent
heat
73,
182
19
curves
potential
energy
41
62–3
149
coulomb
batteries
limit
62–3
elastic
72,
157
60
73
cooling
cars
43,
136–7
elastic
carbon
156
68–9
97
efficiency
capacitors
78
22–3
78–9
of
37
continuous
Bohr
for
115
138
contact
biofuels
40–1,
166
constructive
binary
energy
130
conservation
beta
125
graphs
2
mass
batteries
124,
displacement–time
57
conservation
base
graphs
164
ohmic
balloons
displacement–position
for
(C)
electric
charge
electric
current
see
charge
112
120–1
see
current
40
Index
electric
in
fields
waves
electrical
108–9,
77,
energy
34,
transmission
meters
electrical
power
also
electricity
mains
122
energy
sources
energy
transfer
forces
electromagnetic
induction
generators
electromagnetic
gamma
see
infra-red
70–1,
see
speed
radiation
gamma
73,
eyes
of
80,
118
electromagnetic
spectrum
16,
17
gas
72
gas
31,
110,
decay
in
80,
waves
174
curves
lines
force
(e.m.f.)
36,
induction
in
beta
46–7,
plane
152,
160–1,
particles
charged
circuits
in
electrons
induction
and
90,
92,
de
57
of
state
in
68,
in
118,
45,
66,
9,
62,
charged
between
magnets
107
fields
curves
73
24
169,
characteristics
transfers
144
170
gravity
106–7
12,
40,
106
78–9
124–5
strength
potential
12,
38
energy
38
35
39,
40,
41
12
greenhouse
119
law
of
78
22–3,
24–5
field
transformations
108
160
37
36,
velocity–time
objects
64
55
experiment
22–3,
gravitational
between
Hooke’s
60–1,
69
energy
gravitational
12–13
electric
53
56–7
effect
73
18–19
112
and
immersed
and
impulse
objects
46–7
H
152
ionisation
Van
94–5
90
half-life
28
170–1
80
inter-molecular
in
I-V
163
in
free
liquids
166
objects
112,
36
displacement–time
155
162,
166
displacement–position
gases;
length
164–5,
6–9
decay
68
focal
friction
in
graphs
151
46–7
focal
in
and
175
rule
106
atoms
as
174,
118
forces
electrons
167,
left-hand
also
64
175
172
warming
gradient
120
116,
54,
global
114
see
in
152
26
80–1
fluids
circuits
148,
motion
148–9
floating
in
146,
70
34,
62,
thermometers
currents
18
of
of
56–7
change
169
149
produce
laws
pressure
Fleming’s
cells
natural
gases
81
law
137
167,
81,
emit
geothermal
fission
electromotive
rays
equation
gas
68
149
first
electromagnets
heat
nuclear
tracers
93
field
radiation
175
135
latent
gamma
F
relays
electromagnetism
36,
rectification
G
86
electromagnetic
37
Geiger-Marsden
electromagnetic
infra-red
fusion,
106
115
fuels
134,
fusion,
166
55,
extension
81
114,
43
60–1,
states
exponential
light
fuses
42
76
15,
explosions
80–1
39,
gas,
expansion
rays
full-wave
4–5
excited
152–3
154–5
nuclear
36–7
40,
73,
biofuels
163
66–73
34,
evaporation
12
12,
36,
114–15
waves
errors
fuels
43
161,
movement
55,
equilibrium
113
electromagnetic
a.c.
efficiency
by
106–11
34–5,
charge
friction
energy
40–1,
(fuels)
and
thermal
see
of
electron
and
electrical
115
132–5
static
light
levels,
175
36–7,
35,
energy
114–15
sources
electrolysis
in
153
power
155,
energy
wasted/lost
42
115,
156
electrical
of
transformation
transformations
see
transformation
165
80
Graaff
generators
half-wave
54
rectification
136
108,
in
laws
of
motion
hard
26–7
magnetic
materials
144
109
electrostatic
e.m.f.
see
precipitation
electromotive
and
magnetic
and
moments
34,
of
pressure
state
62,
of
40–1,
equivalence
decay
thermal
capacity
kinetic
fuels
energy
82,
34,
14
internal
energy
36
50
35,
transfers
38
of
35,
43,
36,
73,
transformations
68
115
40,
66,
see
112
also
thermal
41
energy
heating
60
42,
55,
point
62
and
change
68
rate
of
of
state
62–3
79,
98
70–1
174–5
see
of
as
97
potential
see
energy
alternating
current
130,
155
hertz
(Hz)
130
energy
of
transfer
of
34,
electrons
of
potential
34
generation
58
frequency
nuclear
55
electricity
energy
freezing
light
effect
work
freezing
see
expansion
in
166
free
heat
44–5
174
fossil
gamma
kinetic
73
energy
115
and
and
sinks
heat/heat
64
turning
conservation
and
heat
14–15
42
change
mass
150–1
58–9
force
and
and
146,
capacity
111
and
energy
fields
heat
mains
electricity
132,
133
homes,
ring
mains
in
132–3
transfer
on
oscilloscopes
99
Hooke’s
law
18–19,
38
183
Index
human
reaction
human
vision
humidity
times
and
L
M
lamps,
evaporation
hydroelectricity
hyperopia
4
93
61
filament
lasers
37
125
magnetic
82
latent
93
124,
in
heat
62–5
forces
latent
heat
of
fusion
latent
heat
of
vaporisation
62,
64
62,
64
fields
146–7
electromagnetic
from
radiation
80
150–1
in
induction
in
light
152–3,
waves
154–5
77
I
lateral
I-V
characteristics
displacement
lattice
images
vibration
and
66
nuclear
radiation
transformers
165
use
156–7
induction
144–5
85
law
in
86
124–5
lenses
91,
of
conservation
momentum
magnification
immersed
impulse
of
objects
magnets
144–5
94
laws
of
motion
laws
of
reflection
26–7
electromagnets
149
46–7
LDRs
rays
independent
84
magnification
94
(light
variables
6,
lead-acid
cells
current
123
magnifying
left-hand
rule,
mains
glasses
electricity
94
132–5
9
Fleming’s
measuring
151
mass
4
4
and
energy
and
kinetic
conservation
and
momentum
174
152–3
lens
charging
by
formula
94–5
energy
38–9
107
lenses
induction,
resistors)
120–1
107
length,
induction,
dependent
84
charge
induced
magnetic
28–9
28
incident
induced
of
92–3
electromagnetic
90–5
28
152–3,
light
82–3,
96–7
in
second
law
of
motion
26
154–5
diffraction
induction,
magnetic
96
infra-red
86
radiation
70–1,
energy
34,
measurements
35,
82
the
infra-red
greenhouse
effect
thermometers
instantaneous
speed
66,
67,
on
melting
97,
in
lenses
melting
lenses
see
84–5
internal
heat
thermal
resistance
a
86,
as
wave
of
122
mixtures
micrometers
59
4
microprocessors
resistors
microwaves
73,
110
81
123
rays
mirrors,
82
reflection
moderators
at
84,
85
175
lenses
90–1,
formula
92–3
molecules
94–5
54
moments
14–15
125
164,
magnifying
glasses
94
momentum
28–31
165
164,
of
with
84–5
Moon
82–3
165
refraction
conduction
81
91
113,
radiation
77,
50
reflection
112,
of
86,
87,
88
motion,
Newton’s
laws
of
26–7
113
total
isotopes
electrical
method
energy
in
ionising
meters,
90
88
dependent
lens
80,
63
124
97
in
ionisation
62,
112,
120
images
solutions
88–9
86–7,
of
(LDRs)
inverted
point
66,
100
light
internal
metals
9
patterns
energy,
172
54
as
also
101,
60
53
light
internal
work
applications
112
forces
graphs
interference
ions,
4–5
see
22
speed
interference
medical
97
refraction
intercepts
115
interference
total
inter-molecular
ionic
3,
work
73
reflection
insulators
mechanical
81
transformations
see
162
26
as
and
number
144–5
dispersion
inertia
mass
internal
reflection
of
89
motor
effect
150–1,
154
163
lightning
radioisotopes
166,
101,
109
motors,
electrical
myopia
93
154
172–3
limit
line
of
of
proportionality
best
fit
18
8
J
N
linear
joule
(unit)
34,
magnification
94
114
NAND
linear
relationships
gates
natural
liquids
54,
55,
139
8–9
gas
36
68
K
negatively
change
Kelvin
scale
of
state
60–1,
62–3,
neutron
pressure
kinetic
energy
34,
in
number
circuits
logic
of
gates
138,
chain
162
175
139
and
long-sight
39,
40,
in
electrical
energy
isotopes
waves
77,
nuclear
fission
166
167
98
115
newton
loudness
theory
163,
93
41
longitudinal
98,
(N)
12,
26
99
51
Newton’s
lunar
eclipses
laws
of
motion
83
non-contact
184
161,
reactions
35
transformations
from
106,
138–41
60
in
kinetic
107
44–5
neutrons
evaporation
transfers
106,
162
38–9
logic
in
charged
64
51
forces
12
26–7
Index
non-ohmic
conductors
non-renewable
NOR
gates
normals
NOT
84,
gates
86,
138,
energy
nuclear
explosions
nuclear
fission
nuclear
forces
nuclear
fuels
nuclear
fusion
nuclear
model
160
nuclear
power
36,
174–5
plum
fission
36,
in
175
167,
power
nuclear
reactors
in
fission
in
fusion
in
radioactive
in
see
175
162,
166,
144,
163
170–1
radioactive
emissions
radioactive
waste
ray
111
rays
106,
107
(p.d.)
114
130
118,
119
and
charge
transfers
of
52–3
of
51
114,
118
39,
40,
41
84
waves
internal
90
waves
index
refrigerators
regular
100
88–9
86–7,
sound
refuelling
transformations
121
84–5
refractive
35
cells
136–7
rays
sound
total
38
95
secondary
31
refraction
34,
movement
of
91,
reflection
voltage
bonding
rays
recharging
122
and
light
reflected
124–5
98
82
rectification
127
173
172–3
4–5
76,
images
recoil
circuits
energy
see
real
164–75
172
errors
boxes
decay
36
166,
rarefactions
148
difference
also
147
see
dating
radiotherapy
random
146,
thermocouples
potential
168–70
133
160
charged
circuits
and
162
163,
devices
reducing
measuring
160–3
decay
number
magnetic
complex
174
115
81
decay
radiocarbon
model
components
106,
167,
electrical
alternating
167
167,
on
potential
stations
97,
waves
radioactive
radioisotopes
positively
175
37,
83
solenoids
164–5
nuclei/nucleus
cells
camera
pollution,
175
radio
97
pudding
poles,
12
144–5
110–11
98
plugs
174
see
radiation
nuclides
pitch
decay
34,
nuclear
nucleons
pinhole
139
see
magnets
photocopiers
photovoltaic
87
nuclear
nucleon
36
photons
decay
also
sources
139
nuclear
see
permanent
123
energy
100
88–9
73
explosions
reflection
110
84
O
power
ohmic
conductors
122–3,
124,
and
Ohm’s
law
114–15
resistance
126–7
renewable
energy
resistance
122–7
sources
36–7
122–3
of
oil
42,
125
transformers
157
internal
resistance
120
36
power
optical
axis
optical
centre
stations
nuclear
OR
of
fibres
gates
origin
123,
126
lenses
power
36,
175
resolution
4
91
care
101
resultant
force
precision
5
prefixes
3
and
first
law
12,
of
13,
15
motion
26
139
2,
resultant
moment
resultant
vectors
14
22
pressure
oscillations
39,
from
44–5,
76–7,
gas
laws
98–9,
56–7
rheostats
10–11
123
79
pressure
oscilloscopes
55
40
in
waves
resistors
89
138,
9,
155
92
pre-natal
optical
111,
law
57
right-hand
120
ring
grip
rule
148,
149
131
primary
cells
mains
principal
axis
90,
91,
92
ripple
principal
foci
90,
91,
92
r.m.s.
principle
of
132–3
tanks
77,
96
P
parallel
components
resistors
parallelogram
118–19
moments
rule
refraction
nature
of
15
86,
light
96,
76–7,
rockets
87
root
27
mean
98
rough
square
surfaces,
voltage
emission
132
from
70,
71
97
proportionality,
54,
in
10–11
propagation
particles
132
126
prisms,
particle
voltage
limit
of
18
56
S
proton
in
atoms
number
162
106
safety
protons
and
conduction
66,
106,
160,
and
scalars
and
in
evaporation
isotopes
163,
166
scale
waves
theorem
diagrams
78–9
(Pa)
voltage
130,
7,
39,
penetrating
power
penumbra
82–3
semiconductor
164,
radiation
26
99,
164
see
also
diodes
124–5
diodes
see
semiconductors
radiation
sensors
113
140–1
130
in
table
120–1
165
electromagnetic
79,
cells
131
electromagnetic
periodic
motion
40
background
period
of
secondary
radiation
pendulums
law
44
R
peak
10–11
11
second
pascal
134–5
10
60
Pythagoras’
in
electricity
162
68
heat
transfer
70–1,
72,
73
series
components
118,
119
163
radioactive
emissions
164–75
resistors
in
126
185
Index
shadows
shells,
82
electron
short-sight
161,
163
for
logic
for
sensors
systematic
93
gates
139
uranium
140
errors
164,
fission
4,
36,
171,
167,
173
174–5
5
V
SI
units
2–3
T
significant
figures
temperature
sinking
Snell’s
law
and
change
eclipses
72
of
state
and
evaporation
62–3
vaporisation
generators
108–9
60
materials
solenoids
the
gas
laws
60
latent
148–9,
variable
heat
of
62,
resistors
64
123
144
and
heat
and
infra-red
capacity
radiation
37,
58
variables
and
speed
sound
70
vectors
6,
8–9
10–11,
12
72
of
100
velocity
22–3,
24
152–3
temperature
solidifying
56–7
82–3
power/energy
scales
51
and
momentum
28
60
thermal
solids
Graaff
de
88
magnetic
solar
flasks
Van
133
in
solar
50–3
47
sockets
soft
vacuum
5
conductivity
66
velocity–time
graphs
24–5
54
thermal
change
of
state
60,
62–3,
in
66,
34,
virtual
50–1
images
85
64
in
conduction
energy
change
of
state
60
in
lenses
92–3,
94,
95
112
and
geothermal
and
nuclear
and
particles
and
thermal
energy
37
vision
93
sound
as
energy
34,
transformations
speed
of
98,
40,
55,
voltage
of
114
mains
66
and
electricity
rectification
132,
133
136–7
100–1
51,
66–73
transformers
change
156–7
101
nature
of
77,
heat
specific
latent
capacity
see
also
potential
difference
wasted
energy
35
voltmeters
(p.d.)
122
58–9
see
heat
40
98–101
as
specific
also
heat/heat
energy
volume
3,
56–7
64–5
thermistors
speed
175
conductivity
transformations
wave
36,
68
115
transfers
ultrasound
power
35
123
22
W
thermocouples
of
electromagnetic
radiation
52–3
80,
wasted/lost
thermometers
energy
35,
40–1,
52–3
86
water,
third
light
86,
law
of
motion
energy
power
watt
of
sound
98,
of
waves
79
waves
77,
measuring
(W)
42,
wave
base
nature
commutators
of
internal
reflection
pulses
wavefronts
18,
81,
77,
wavelength
76,
96
172
19
transformation
18–19,
96–7
76
88–9
154
tracers
constant
light
131
wave
total
springs
97
114
4
100–1
time
spring
96,
37
38–9
time,
split-ring
87
27
water
kinetic
in
88
tidal
and
refraction
of
energy
78,
79
34–5,
77
waves
76–81
39
stability
16–17
a.c.
electrical
stable
equilibrium
waveforms
diffraction
in
standard
form
induction
153,
energy
fusion
in
96
154
2
loss
stars,
167,
to
surroundings
transfer
interference
of
matter
sound
of
state
waves
76–7,
truth
electricity
tables
also
effect
wind
two-slit
experiment
objects
46,
35,
38
heating
73,
effect
of
50
47
ultrasound
in
101
induction
153
167
ultraviolet
eclipses
34,
47
U
submerged
37
97
60
submarines
light
81
and
power
42
82–3
umbra
surface
16
turbines
work
37,
12,
14
18
sublimation
area
60,
82–3
70
X
uncertainty
4–5
surfaces
X-rays
units
pressure
on
radiation
emission
186
116–17,
123
equilibrium
70–1
17
Z
upthrust
symbols
81
2–3
44
unstable
and
76
98–101
138–9
weight
Sun
77,
light
106–11
turning
stiffness
waves
80
60–5
see
static
34,
97
156–7
54–5
transverse
change
by
40–1
175
transformers
states
130–2
115
17
12,
47
zinc-carbon
dry
cells
120
43
Acknowledgements
The
author
permission
Alamy:
Aurora
A.T
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Getty
Lunardi:
Images:
4.24.2,
Works
5.5.1;
&
1.2.1,
Corbis:
Bert
1.20.1,
f.
effort
the
2.6.3;
has
necessary
Library:
thank
the
following
Researchers,
made
4.5.1,
3.4.1,
to
2.2.1;
for
3.13.4,
Inc:
Vidéo
1.9.1,
trace
arrangements
the
the
at
du
NASA:
4.20.4,
Staples:
CSG:
Hart
1.8.4;
Davis:
1.12.3,
1.5.1;
SuperStock:
2.12.4.
copyright
first
4.13.3;
2.6.4;
Transport,
Adrienne
publisher
the
of
Darren
Library:
Commons:
overlooked
Ocean:
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Metta
4.12.2,
Fotolia:
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Clive
John
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1.8.2;
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4.14.1,
Lyroky:
2.7.1,
Reuters:
Optique
Images:
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Green:
Inspirestock:
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/
Arcaid
Chris
J.
Hoferichter:
1.1.1;
Wikimedia
been
1.18.2,
2.9.4,
Science
inadvertently
to
4.19.2,
David
Chillmaid:
Jamaica:
1.12.1;
like
sciencephotos:
ESA-CNES-ARIANESPACE
been
make
Picture
5.8.1,
1.15.3,
Housing,
Stockbroker:
have
2.12.2,
1.14.2;
GIPhotoStock/Photo
Every
Images:
Martyn
Features:
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Blend
Garland
AFP:
also
Alchemy:
Lyons:
Rachko:
iStockphoto:
Rex
2.3.3,
would
material:
4.17.1,
David
Leslie
4.18.1,
Simone
publisher
Willett:
4.8.2,
1.21.2,
Stock:
the
reproduce
Photos:
Streeter:
NZ:
and
to
holders
will
be
but
if
any
pleased
to
opportunity.
187
Physics
for
CSEC®
Achieve your potential
Developed
guide
in
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exclusively
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Physics
an
syllabus
information
key
●
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to
Engaging
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designed
●
the
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Examinations
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Physics.
Written
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with
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that
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this
study
double-page
from
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help
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of
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and
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covers
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syllabus
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Each
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Examination
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This
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Physics
The
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Nelson
Pa r t
CD,
University
P re s s
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