Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
CHAPTER 1 : INTRODUCTION TO PHYSICS
1.1 Understanding Physics
PHYSICS
Mechanical Energy
Study of the natural phenomena and the
properties of matter.
Matter
Solid
Heat Energy
Light Energy
Energy
Wave Energy
Liquid
states
forms
Electrical Energy
Gas
Nuclear Energy
Chemical Energy
Properties of
Matter
Relationship
with
matter
Relationship
with
energy
Properties of
Energy
in the fields
Mechanics
Properties
of matter
Wave
Heat
Electronics
Electricity &
Electromagnetism
Light
1
Atomic Physics
& Nuclear
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
1.2
PHYSICAL QUANTITIES
Base quantity
1
2
3
any quantity that can be measured by a scientific instrument.
A physical quantity is ……………………………………………………………………..
stopwatch, metre rule balance,thermometer,ammeter
Examples of scientific instruments :………………………………………………………
etc.
A base quantity is a physical quantity which cannot be defined in terms of other physical
quantities.
4
Study the following picture and list the physical quantities that can be measured.
The list of physical quantities :
Height,
1. ……………………………………….
mass,
2. ……………………………………….
size,
3. ……………………………………….
age,
4. ……………………………………….
temperature,
5. ……………………………………….
current
6. ……………………………………….
Power,
7. ……………………………………….
Thermal energy
8. ……………………………………….
battery
5
List of 5 basic physical quantities and their units.
Base quantity
6
Symbol
S.I. Unit
Symbol for S.I. Unit
Length
l
Mass
m
kilogram
kg
Time
t
second
s
Current
I
Amppere
A
Temperature
T
Kelvin
K
meter
m
Two quantities that have also identified as basic quantity. There are :
Light intensity
candela ii) ……………………….
Amount of substance unit ……………..
mol
i) …………………………..unit
…………..
2
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Standard Form
1 Standard form = A x 10 n ,
2
1 < A < 10 and n = integer
simplify the expression of very large and small numbers
Standard form is used to …………………………………………………………………...
3
Some physical quantities have extremely small magnitudes. Write the following
quantities in standard form :
6.37 x 106 m
a. Radius of the earth = 6 370 000 m =………………………………………………….
1.673 x 10-27 kg
b. Mass of an electron = 0.000 000 000 000 000 000 000 000 000 000 911 kg =………...
3.0 x 10 -4 m
c. Size of a particle = 0.000 03 m = ………………………………………………………
7.2 x 10 -8 m
b. Diameter of an atom = 0.000 000 072 m = …………………………………………...
5.5 x 10-7
c. Wavelength of light = 0.000 000 55 m = ……………………………………………..
Prefixes
represent a large physical quantity or extremely small quantity in S.I
1. Prefixes are usually used to ………………………………………………………………...
units.
before the unit as a multiplying factor.
2. It will be written ……………………………………………………………………………
3. The list of prefixes :
12
Tera (T)
9
Giga (G)
6
Mega (M)
10
10
10
2
103 101
10
100 10
10
10
-3
10
-6
10-9
10
-12
-1
-2
kilo (k) Hekto (ha)
Deka (da)
desi (d)
centi (s)
mili (m)
Eg :
1 x 1012 m
1 Tm = …………………………………….
3.6 x 10-3A
3.6 mA = …………………………………….
How to change the unit ;
Eg :
1. Mega to nano
1.33 MA = 1.33 x 106 A
= 1.33 x 10 6-(-9) nA
= 1.33 x 10 -15 nA
micro ()
2. Tera to micro
nano (n)
1.23 Tm to unit m unit
1.23 Tm = 1.23 x 10 12m
= 1.23 x 10 12 – (-6)m
pico (p)
= 1.23 x 10 18m
5456 pA to MA unit
5456 pA = 5.456 x 10 3 + (-12) pA
3. piko to Mega
= 5.456 x 10 -9 pA
= 5.456 x 10 -9 –(6) MA
= 5.456 x 10 -15 MA
4. Some physical quantities have extremely large magnitudes. These extremely large and
small values can be written in standard form or using standard prefixes. Write the
quantities in standard prefixes:
9.1 x 10 1MHz
a. Frequency of radio wave = 91 000 000 Hz = ………………………………………….
1
12.8 Mm = 1.28 x 10 Mm
b. Diameter of the earth = 12 800 000 m = ………………………………………………
2
383 Mm = 3.83 x 10 Mm
c. Distance between the moon and the earth = 383 000 000 m = ………………………
6.0 x 10 12 Tm
d. Mass of the earth = 6 000 000 000 000 000 000 000 000 kg = ………………………
3
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Derived quantities
1
a physical quantity which combines several basic quantities
A derived quantity is …….…………………………………………………………………
through multiplication, division or both
………………………………………………………………………………………………
2
Determine the derived unit for the following derived quantities.
Derived
quantity
Formula
Derived unit
Name of
derived unit
area
area = length x width
m x m = m2
–
volume
density
velocity
momentum
Acceleration
Force
pressure
volume = length x width x height
density 
velocity 
mass
volume
m
displacement
time
change in velocity
time
force = mass x acceleration
pressure 
force
area
weight = mass x gravitational acceleration
work
work = force x displacement
work
time
power 
kinetic energy
1
K.E   mass  velocity 2
2
potential
energy
P.E = mass x gravitational acceleration x height
charge
charge = current x time
work
charge
voltage
voltage 
resistance
resistance 
3
 kg m 3
voltage
current
–
–
m
 m s 1
s
–
kg m s-1
–
m s 1
 m s -1 s 1
s
 m s 2
kg m s-2
kg m s-2 / m2
weight
power
mxmxm=m
kg
momentum = mass x velocity
accelerati on 
3
kg ms -2
–
Newton (N)
kg m-1 s-2
(Nm-2)
Newton (N)
Nm
Joule (J)
J s -1
Watt (W)
Kg ms-2
Joule (J)
Kg ms-2
Joule (J)
Ampere second
(As)
Coulomb (C)
J C-1
Volt (v)
v A-1
Ohm (Ω)
Note that the physical quantities such as width, thickness, height, distance, displacement,
perimeter, radius and diameter are equivalent to length.
4
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
1.3
1
2
3
SCALAR AND VECTOR QUANTITIES
Quantity which has only magnitude or size
Scalar quantities are ………………………………………………………………………
Mass, Length, Speed, volume
Examples : …………………………………………………………………………………
Quantity which has magnitude or size and direction.
Vector quantities are………………………………………………………………………...
Velocity, Force, Displacement, Acceleration
Examples : …………………………………………………………………………………
Study the following description of events carefully and then decide which events require
magnitude, direction or both to specify them.
Description of events
Magnitude
1. The temperature in the room is 25 0C
Ý
2. The location of Ayer Hitam is 60 km to the
north-west of Johor Bahru
Ý
Direction
Ý
3. The power of the electric bulb is 80 W
Ý
4. A car is travelling at 80 km h-1 from Johor Bahru
to Kuala Lumpur
1.4
Ý
Ý
MEASUREMENTS
Using Appropriate Instruments to Measure
1
measuring instrument with different measuring capabilities.
There are various types of………………………………………………………………….
2
measure a particular quantity.
We must know how to choose the appropriate instrument to ……………………………..
3
Examples of instrument and its measuring ability.
Measuring instrument
Measuring tape
Meter rule
Vernier caliper
Micrometer screw gauge
Range of measurement
Up to a few meters
1m
Smallest scale division
0.1 cm
0.1 cm (0.01 m)
10 cm
0.01 cm
less than 2 cm (20 mm)
5
0.001 cm (0.01 mm)
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
4
Sample of measuring instruments :
is use to measure electric current
4.1 Ammeter : ……………………………………………………………………………..
1
incorret reading
2
1
3
0
4
pointer
2
3
0
pointer
mirror
correct
4 reading
mirror
Pointer’s image is behind the pointer
Pointer’s image can be seen
is use to determine the volume of liquid.
4.2 Measuring cylinder : ……………………………………………………....................
wrong position of eye
Right position of eye (eye are in a line perpendicular to the plane
of the scale)
wrong position of eye
water
is use to determine the length
4.3 Ruler : ………………………………………………………………………………………
wrong
10
11
right
12
wrong
13
14
15
Reading = ……………… cm
4.4 Vernier calliper
A venier calliper is used to measure :
small object
depth of a hole
external diameter of a cylinder or pipe
internal diameter of a pipe or tube
a. ………………………………………………b. ………………………………………….
c. ………………………………………………d. ………………………………………….
0.01 cm
A vernier calliper gives readings to an accuracy of …………………………………...…. cm.
inside jaws
scale1
cmVernier
0
2
3
4 Main scale
SKALA
0
outside jaws
Main scale in cm
0.9
Length of vernier scale = ……… cm
0
1
Vernier scale is divided into 10 divisions
0.09
Length of the divisions = ………. cm
0
5
10
Vernier scale
The differenct between the main scale and vernier
0.01 cm
scale is = …………………………….
cm
6
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
0
cm
Main scale
1
0.2 cm
= ………………….
0
1 2 3 4 5
6 7 8 9 10
Find the division of
vernier scale which is
coincides with any part
of the main scale
0.06 cm
Vernier scale = …………………..
0.26 cm
Final reading = …………………..
The diagram below shows a vernier calliper with reading.
0
1
0
5
0.15
Vernier calliper reading = ……………. cm
10
4.5 Micrometer screw gauge.
A micrometer screw gauge is used to measure :
objects that are small in size
a. ………………………………………………
diameter of a wire
b. ………………………………………….
diameter of small spheres such as ball bearings
c. ………………………………………………
One complete turn of the thimble
(50 division) moves the spindle by
0.50 mm.
Division of thimble
0.5 ÷ 50
= …………………..
0.01 mm
= …………………..
A accuracy of micrometer
0.01 mm
screw gauge = ……………..
4.5 mm
Sleeve scale : ……………
0.22 mm
Thimble scale : ………….
4.62 mm
Total reading : …………..
Example :
2.0 mm
Sleeve scale : ……………
0.22 mm
Thimble scale : ………….
2.22 mm
Total reading : …………...
7
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
4.6 Some others measuring instruments :
Analogue stopwatch
digital stopwatch
……………………… ……………………
Measuring tape
……………………….
thermometer
miliammeter
……………………… ………..
measuring cylinder
……………………..
beaker
………………
Hands-on activity 1.1 on page 1 of the practical book to learn more about choosing
appropriate instruments.
Exercise: Vernier Callipers And Micrometer Screw Gauge
1. Write down the readings shown by the following
(a)
7
8
5
0
(b)
4
A
B
10
Answer: …7.79 cm…………..
5
Answer: …4.27 cm…………..
P
0
Q
10
5
6
(c)
7
Answer: ……6.28 cm………..
0
(d)
1
5
1
0
Answer: …0.02 cm…………..
0
10
5
8
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
2. (a) The following diagram shows the scale of a vernier calliper when the jaws are closed.
1
0
0
10
5
Zero error = …0.02……… cm
(b).
The following diagram shows the scale of the same vernier calliper when there are
40 pieces of cardboard between the jaws.
5
6
0
Reading shown
10
5
= …5.64…….cm
Corrected reading = …5.62……..cm
3.
Write down the readings shown by the following micrometer screw gauges.
(a)
(b)
0
40
5
0
5
35
10
35
30
Answer: ………………………….
Answer:…………………..
(c)
(d)
25
0
0
5
20
20
15
Answer:…………………………
Answer:…………………….
4. (a) Determine the readings of the following micrometer screw gauges.
0
0
0
45
5
0
Zero error = …0.02…….. mm
Zero error = …0.03…….. mm
9
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
(b) Determine the readings of the following micrometer screw gauges.
0
5
0
20
5
0
15
Zero error = 0.03………mm
Reading shown
= 6.67………..mm
Corrected reading = 6.64………..mm
5. Write down the readings shown by the following micrometer screw gauges.
(a)
(b)
0
40
5
0
5
35
10
35
30
Answer: …6.88 mm…………
Answer: …..12.32 mm……
(c)
(d)
25
0
0
20
5
20
15
Answer:………4.71 mm…………
Answer:
9.17 mm…………
6. (a) Determine the readings of the following micrometer screw gauges.
0
0
0
45
Zero error = …-0.02 mm
5
0
Zero error = …0.03.. mm
(b) Determine the readings of the following micrometer screw gauges.
0
0
5
0
Zero error = …0.03.mm
5
20
15
Reading shown
= ….6.67..mm
Corrected reading = …6.64..mm
10
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Accuracy and consistency in measurements.
The ability of an instrument to measure nearest to the actual value
1. Accuracy : …………………………………………………………………………………
The ability of an instrument to measure consistently with little or no relative
2. Consistency : ………………………………………………………………………………
deviation among readings.
The ability of an instrument to detect a small change in the quantity measured.
3. Sensitivity : …………………………………………………………………………………
target
consistent but inaccurate
consistent and accurate
inaccurate and not consistent
………………………… ………………………
……………………………..
target
Accurate
but not consistent
inaccurate but consistent
inaccurate but not consistent
……………………..
……………………………..
………………………………
Hands-on activity 1.2 on page 2 of the practical book to determine the sensitivity of
some measuring instruments.
Errors in measurements
of approximation only.
1. All measurements are values ………………………………………………………………
how close the measurement is to the actual value.
2. In other word, it is a matter of ……………………………………………………………
error exist in all measurements.
3. This is because ……………………………………………………………………………
4. Two main types of errors:
Systematic errors
4.1 ……………………………………………
Occurs due to :
a weakness of the instrument
a) ………………………………………………………………………………………
the difference between reaction time of the brain and the action.
b) ………………………………………………………………………………………
zero error is when the pointer is not at zero when not in use.
c) ………………………………………………………………………………………
Examples :
Range of the measuring instrument – absolute error .
a) ………………………………………………………………………………………
Reaction time of the brain.
b) ………………………………………………………………………………………
Initial reading is not at the zero scale – zero error
c) ………………………………………………………………………………………
11
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Absolute error :
Refer to the smallest reading that can be measured by an instrument.
……………………………………………………………………………………….…………
………………………………………………………………………………………………….
Example :
If, the smallest reading = 0.1 cm
Then, Absolute error = 0.1 / 2 = 0.05 cm
It occurs because the position of the eye is not perpendicular to the scale of
Parallax error : ………………………………………………………………………………
the instrument.
wrong
right position of the eye (no error)
wrong
0
1
0
cm
0 1 2 3 4 5 6 7 8 9 10
1
cm
0 1 2 3 4 5 6 7 8 9 10
Zero error =
+0.03 cm
Zero error =
– 0.04 cm
where the pointer is not at zero when not in use
Zero error : …………………………………………………………………………………...
Correct reading = observed reading – zero error
Positive zero error
Horizontal
reference
negative zero error
2 divisions below
horizontal reference
Zero error = +0.02 mm
Horizontal
reference
3 divisions above
horizontal reference
Zero error = –0.03 mm
Positive zero error
Zero error of screw meter gauge
12
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Random error
4.2 ……………………………………………..
Occurs due to
carelessness in making the measurement.
a) ………………………………………………………………………………………
parallex error , incorrect positioning of the eye when taking the readings.
b) ………………………………………………………………………………………
sudden change of ambient factors such as temperature or air circulation.
c) ………………………………………………………………………………………
Example :
Readings are close to the actual value but they are not consistent.
a) …………………………………………………………………………………..…
Can be minimized by consistently repeating the measurement at different places in
b) ……………………………………………………………………………………..
an identical manner.
.....................................................................................................................
1.5
SCIENCETIFIC INVESTIGATION
Steps
Explanation
1
Making
observation
Gather all available information about the object or
phenomenon to be studied.
Using the five senses, sight, hearing, touch, taste and smell.
2
Drawing
inferences
A conclusion from an observation or phenomena using information
that already exist.
Variables are factors or physical quantities which change in
the course of a scientific investigation.
There are three variables :
i. Manipulated variables – physical quantity which changes
according to the aim of the experiment.
ii. Responding variables – physicals quantity which is the
result of the changed by manipulated variable.
iii. Fixed variables – physicals quantities which are kept
constant during the experiment.
3
Identifying
and controlling
variables
4
Formulating a
hypothesis
Statement of relationship between the manipulated variable and
the responding variable those we would expect.
Hypothesis can either be true or false.
5
Conducting
experiments
i. Conduct an experiment includes the compilation and
interpretation of data.
ii. Making a conclusion regarding the validity of the hypothesis.
13
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Plan and report an experiment
Situation : A few children are playing on a different length of swing in a
playground. It is found that the time of oscillation for each swing is different.
Steps
1
Inference
2
Hypothesis
3
Aim
4
Variables
5
List of
apparatus and
materials
6
Example : refer to the situation above
The period of the oscillation depends on the length of the
pendulum.
When the length of the pendulum increases, the period of the
oscillation increases.
Investigate the relationship between length and period of a
simple pendulum.
Manipulated variable : the length of the pendulum.
Responding variable : Period
Fixed variable : the mass of the pendulum and the
displacement.
Retort
stand
withbob,
clamp,
100 cm
of thread,
bob,
Retort
stand,
metal
thread,
stopwatch,
protractor,
metre
rule,
Arrangement of
the apparatus
Retort stand
protractor
ll
bob
7
Procedures
1. Set up the apparatus as shown in the figure above.
2. Measure the length of the pendulum,l = 60.0 cm by using a meter
rule.
3. Give the pendulum bob a small displacement 300.Time of
10 oscillations is measured by using a stop watch.
4. Repeat the timing for another 10 oscillations. Calculate the
average time.
Period = t10 oscillations
10
5. Repeat steps 2, 3 and 4 using l = 50.0 cm, 40.0 cm, 30.0 cm
and 20.0 cm
14
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
8
Tabulate the
data
Time for 10 oscillations / s
2
1
Average
Length,l /
cm
6 0 .0
5 0 .0
4 0 .0
3 0 .0
2 0 .0
9
Analyse the
data
T/s
15.8
15.0
13.1
11.9
9 .9
1 5 .7
1 5 .0
1 3 .1
1 1 .9
9.9
15.8
15.0
13.1
11.9
9 .9
Period/ s
(T = t10/10)
1 .5 8
1 .5 0
1 .3 1
1 .1 9
0 .9 9
Graf of period, T vs
pendulum’s length, l
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
10 Discussion
11 Conclusion
Precautions
12 step
10
20
30
40
50
60 l / cm
Precautions :
1. Oscillation time is measured when the pendulum attained a
steady state.
2. Time for 10 oscillations is repeated twice to increase accuracy.
3. Discussion (refer to given questions)
The period increases when the length of the pendulum increases.
Hypothesis accepted.
1. avoid from strong wing blowing
2. use small amplitude
3. time taken at the equilibrium position
15
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Reinforcement Chapter 1
Part A :Objective Question
10. The diameter of a particle is 250 m.
What is its diameter in cm?
A 2.5 x 10-2
B 2.5 x 10 -4
C 2.5 x 10-6
D 2.5 x 10 -8
1. Which of the following is a base SI
quantity?
A Weight
B Energy
C Velocity
D Mass
11. Which of the following prefixes is
arranged in ascending order?
A mili, senti, mikro, desi
B mikro, mili, senti, desi
C mili, mikro, desi, senti
D desi, mikro, mili, senti
2. Which of the following is a derived
quantity?
A Length
B Mass
C Temperature D Voltage
3. Which of the following is not a basic
unit?
A Newton
B kilogram
C ampere
D second
12. Velocity, density, force and energy are
A basic quantities
B scalar quantities
C derived quantities
D vector quantities
4. Which of the following quantities
cannot be derived?
A Electric current B Power
C Momentum
D Force
13. Which of the following shows the
correct conversion of units?
A 24 mm3 =2.4 x 10-6 m3
B 300 mm3=3.0 x 10 -7 m3
C 800 mm3=8.0 x 10 -2 m3
D 1 000 mm3=1.0 x 10-4 m3
5. Which of the following quantities is
not derived from the basic physical
quantity of length?
A Electric charge B Density
C Velocity
D Volume
14. Which of the following measurements
is the shortest ?
A 3.45 x 10 3 m
B 3.45 x 10 4 cm
C 3.45 x 10 7 mm
D 3.45 x 10 12 m
6. Initial velocity u, final velocity v,
time t and another physical quantity k
is related by the equation v - u = kt.
The unit for k is
A m s-1
B m-1 s
C m s-2
D m2 s-2
15. The Hitz FM channel broadcasts radio
waves at a frequency of 92.8 MHz in
the north region. What is the frequency
of the radio wave in Hz?
A 9.28 x 10 4
B 9.28 x 10 5
7
C 9.28 x 10
D 9.28 x 10 10
7. Which of the following has the
smallest magnitude?
A megametre
B centimetre
C kilometre
D mikrometre
16. An object moves along a straight line
for time, t. The length of the line, s is
1
given by the equation s  gt 2 . The
2
SI unit of g is
A m2 s2
B m s-2
-1
C s
D s-2 m
8. 4 328 000 000 mm in standard form is
A 4.328 x 10-9 m B 4.328 x 10 -6 m
C 4.328 x 106 m D 4.328 x 10 9 m
9. Which of the following measurements
is the longest?
A 1.2 x 10-5 cm B 120 x 10-4 dm
C 0.12 mm
D 1.2 x 10 -11 km
16
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
Part B : Structure Question
1. A car moves with an average speed of 75 km h-1 from town P to town Q in 2 hours as
shown in Figure 1. By using this information, you may calculate the distance between the
two towns.
P
Q
Figure 1
(a) (i) Based on the statements given, state two basic quantities and their respective
SI units.
Distance : m and time : s
………………………………………………………………………………………
(ii) State a derived quantity and its SI unit.
Speed – m s-1
………………………………………………………………………………………
(b) Convert the value
3
1 . m to standard form.
5 x 10-3
= 0.2 x 10 m
= 2.0 x 102 m
(c) Complete Table 1 by writing the value of each given prefix.
-9
10
-6
10
6
10
9
10
Table 1
(d) Power is defined as the rate of change of work done. Derive the unit for power in
terms of its basic units.
work
Force  displacement
kgms 2  m
Power =
=
Unit =
= kg m2 s-3
time
time
s
(e) Calculate the volume of a wooden block with dimension of 7 cm, 5 cm breadth and 12
cm height in m3 and convert its value in standard form.
-2
-2
-2
Volume = (7 x 10 ) (5 x 10 ) (12 x 10 )
-6
= 420 x 10
-4
3
= 4.20 x 10 m
17
Physics Module Form 4
Teacher’s Guide
Chapter 1 : Introduction To Physics
_________________________________________________________________________________________
2. Figure 2 shows an ammeter of 0—3 A range.
Figure 2
Mirror
(a) (i) Name component X. ………………………………………………………………...
To avoid parallax error
(ii) What is the function of X? ………………………………………………………….
(b) Table 2 shows three current readings obtained by three students.
Table 2
No
(i) Did all the students use the ammeter in Figure2? ..………………………………….
(ii) Explain your answer in (b)(i).
3 rd readings obtained by student 2 and 3 are out of the meter range.
………………………………………………………………………………………
3. Figure 3 shows the meniscus of water in a measuring cylinder K, L, and M are three eye
positions while measuring the volume of the water.
(a) (i) Which of the eye positions is correct while
taking the reading of the volume of water?
L
…….……………………………………
Figure 3
(b) The water in the measuring cylinder is
replaced with 30 cm3 of mercury.
(i) In Figure 4, draw the meniscus of the
mercury in the measuring cylinder.
Figure 4
(ii) Explain why the shape of the meniscus of mercury is as drawn in (b)(i).
The cohesive force is larger than the adhesive force
………………………………………………………………………………………
18