NCEA Level 1 Physics (90182) 2010 — page 1 of 5
Assessment Schedule – 2010
Physics: Demonstrate understanding of wave and light behaviour (90182)
Note: Minor computational errors will not be penalised. A wrong answer will be accepted as correct provided there is
sufficient evidence that the mistake is not due to a lack of understanding. Such evidence includes:
 the last written step before the answer is given has no unexpanded brackets or terms and does not require rearranging.
 the power of any number that is multiplied by a power of 10 is correct.
Correct units and significant figures are required only in the questions that specifically ask for them.
Italics indicate replacement evidence.
Evidence Statement
Question
ONE
(a)
Evidence
The particle will either:
 move back and forth / side to side / to &
fro / left to right
OR
 oscillate / vibrate parallel to direction of
wave / longitudinal(ly).
(b)
Achievement
with Merit
Achievement
1
Correct answer.
2
Correct working or
answer.
2
Correct wavelength
calculated or correct
calculation with
wrong wavelength /
d.
1
correct process /
error carried
forward from 1(b).
1
T
1
T
 1.5  103 ΚsΚΚΚ(0.0015Κs)
670
or 1.49  10 Π3 ΚsΚΚ
f 
(c)
4.5
 0.50Κm
9
v  f   670  0.50

 335ΚorΚ340Κms Π1
OR
d
0.5Κm
335
v 
ΚΚ=Κ
ΚmΚs 1
Π
3
t 1.49  10 Κs
340
2
Correct working
and answer.
Achievement
with Excellence
NCEA Level 1 Physics (90182) 2010 — page 2 of 5
(d)(i)
Larger amplitude with the same frequency.
(ii)
Same amplitude with the greater frequency.
(iii)
Higher pitch has greater number of waves
per second.
(e)
1 Particle at A moves up and down.(not
down and up)OR up and then back to
original position. (any discussion of
particle moving towards shore negates
this point)
1
A sketch of larger
amplitude with the
same frequency
OR
same amplitude
with the greater
frequency
OR
definition of
frequency being
number of waves
per second.
1
Link between
sketch of larger
amplitude with
the same
frequency
AND
same amplitude
with the greater
frequency.
OR
ONE sketch plus
link between
frequency and
period / more
waves in time
frame or 1 second
etc
OR
Use v = f  to
explain
wavelength
decreasing as
frequency
increases (do not
allow wavelength
decreases just
from graph)
OR
ONE sketch plus
definition.
1
States EITHER 1
OR 2.
1
States BOTH 1
AND 2.
2
Correct answer for
frequency.
2
Correct working
and answer for
wavelength 4.0 m
at the centre of
the lake.
1
Both sketches
correct with clear
link between
frequency and
period / more
waves in
timeframe
OR
Both sketches
plus link between
frequency,
wavelength and
speed using
equation v = f 
NOT graph.
2
Correct working
and answer.
2 The direction of the movement of the
particle is at 90° to the wave direction /
transverse(ly) (any discussion of
longitudinal movement negates this
point)
(f)
TWO
(a)
12
 0.20
60
v 0.80
 
 4.0Κm
f 0.20
WavelengthΚnearΚtheΚshore
3
=  4  3.0Κm
4
3
OR  0.8  0.6ΚmΚsΚ
4
ANDΚd  0.6  5  3Κm
f 
0.80 + 0.80 + 0.80 + 1.2 + 0.80 +1.2
= 5.6 m
OR
ONE correct
process.
OR
TWO correct
processes.
2
Correct working or
answer.
NCEA Level 1 Physics (90182) 2010 — page 3 of 5
(b)
(c)
48°
(d)
OR
The ray bends / refracts away from the
normal because it is travelling faster in air
compared to water / water has a higher
refractive index / water is more optically
dense. The human eye projects the image in
a straight line.
1
Correct ray diagram
ie reflection at
mirror A followed
by mirror B.
2
Indicates angle of
reflection on mirror
B is 42° OR angle
with mirror A is 42°
OR
explanation of how
angle of 42° is
calculated eg 90° –
48° = 42°
OR
angle measured to
normal
Cannot just state
answer without
any evidence.
1
Diagram shows
correct relative
angles between ray
in air and ray in
water.
Correct answer.
1
Correct diagram
showing virtual
ray to image and
actual ray from
fish.
OR
OR
1
1
States that light
bends / refracts
away from the
normal when light
moving into air /
towards normal
when entering
water.
Correct
explanation ie
light is seen as if
it had travelled in
a straight line.
MUST use the
term refracts, not
bends.
1
As for Merit but
with dotted line to
show virtual rays
to virtual image
PLUS arrows
which MUST be
in the correct
direction / written
indication of
direction of light
OR
Explanation as for
Merit AND
reference to
virtual image
formed when
straight line ray
tracks back.
MUST use the
term refracts, not
bends.
NCEA Level 1 Physics (90182) 2010 — page 4 of 5
(e)
1. This is caused by the dispersion of light
by water.
2. The colours appear because the water is
refracting the light twice in the same
direction so colours are separated
because they refract at different angles on
entering a different medium.
3. This is because different colours, which
have different wavelengths / frequencies
travel at different speeds in water (the
water has a different refractive index for
different colours). This causes different
colours to refract at different angles.
1
States that
dispersion causes
rainbow colours.
OR
Refraction at 2
interfaces both
refracting in the
same direction
1
OR
link between
wavelength and
change in speed
OR
Unlabelled diagram
showing dispersion
at both interfaces.
Links different
angles of
refraction / degree
of refraction to
different
wavelengths /
frequencies /
speeds / optical
densities (or
shows in diagram
ie labels colours
of rays) / red
refracts least &
violet refracts
most.
1
Correct clear and
concise
explanation in
terms of different
angles of
refraction at 2
boundaries and
any of:
• speed
• refractive index
• optical density
• wavelength
• frequency
Not colour.
Must include term
dispersion.
Must use term
refraction, not
bending.
Must use term
refraction not
bending.
Do not allow
different colours /
wavelengths have
different refractive
indices.
(f)
n1 v2
v2
1.00



n2 v1
1.33 3.0  108
2.The speed of light in the fluid is:
2
ONE correct
process.
2
TWO correct
processes
1
Correct working or
answer in metres.
OR
Correct working
with one mistake
eg dividing d by 2
ONE correct
process.
2
Correct working
or answer in km.
2
ONE correct
process
eg
correct answer for
velocity.
OR
Used the wrong
value for velocity,
but shows the
correct follow-on
method.
Eg used v as
340 m s–1 from (a).
2
TWO correct
processes
eg
Correct working
and answer but
used d instead of
2d to get 117.3 m.
1.
2
THREE correct
processes.
2
Correct working
and answer.
3.0  108  1.00
 2.26  108 m s –1
1.33
The speed of light in the lens is:
v2 
3.vl 
95  2.26  108
 2.14  108 m s –1
100
(Accept 2.13  108 m s –1 )
THREE
(a)
v
d
t
d
7.6
d  (340  7.6)
340 
 2 584 m
 2.6 km
(b)
v  f   23 000  0.015
 345 m s 1
2d  v  t  345  0.34  117.3 m
117.3
d
2
 58.7 m
Can also use 0.17 s as time instead of
dividing final distance by 2
NCEA Level 1 Physics (90182) 2010 — page 5 of 5
(c)
We cannot hear ultrasound because it is a
high frequency sound and it is beyond the
range of our audible frequency. So it needs
to be changed into the audible frequency
range.
1
States that we
cannot hear
ultrasound
OR
so that person can
hear it
do not accept
cannot hear very
high frequency.
1
Describes in
terms of
frequency range
OR
frequency too
high to hear.
(d)
1 He will get an echo from each vertical
section of the bus shelter first (one on the
right ear and the other on the left ear).
2 He will get no echo from the space
between the vertical walls.
3 He should get delayed echo from the seat
(because it is further in from the vertical
walls).
1
States that he will
receive the echo /
reflection / sound
from some places
OR
not receive echo /
reflection from
some / other places.
1
States that he will
receive the
reflection / echo /
sound from some
places
AND
not receive echo /
reflection from
other places.
Judgement Statement
Achievement
Achievement with Merit
Achievement with
Excellence
4 A1
3 A1 + 3 M1
3 A1 + 3 M1 + 1 E1
5 A2
3 A2 + 4 M2
3 A2 + 3 M2 + 2 E2
1
Correctly links
reflection / no
reflection to
shelter / back of
shelter
respectively –
must use echo /
reflection, not
just sound.