1
1
(a) A loudspeaker is producing a sound.
Choose words from the box to complete the sentences about sound.
amplitude
(i)
frequency
speed
wavelength
To increase the loudness of the sound, increase the .............................................. of
the
sound wave.
[1]
(ii) To increase the pitch of the sound, increase the .............................................
of thesound wave.
(b) Two students determine the speed of sound in air.
The students stand together, 80 m from a large brick wall as shown in Fig. 8.1.
brick wall
80 m
Fig. 8.1 (not to scale)
One student shouts and as he shouts the other student starts a stop-watch. She
stops thestop-watch when she hears the echo of the shout.
The reading on the stop-watch is 0.56 s.
(i)
State the total distance the sound travels during the 0.56 s.
distance = ..................................................... m [1]
(ii)
Calculate the speed of sound in air using the measurements given in part (b).
speed of sound = ................................................. m / s [3]
[1]
2
7
Fig. 7.1 shows a floating plastic ball attached by a long rope to a weight on the bottom of a lake.
A water wave on the surface of the lake causes the ball to move vertically up and down.
ball
direction of travel of the water wave
24 cm
rope
weight
Fig. 7.1
(a) On Fig. 7.1, show the wavelength of the wave. Label the distance W.
[1]
(b) Determine the amplitude of the wave.
amplitude =...................................................... cm [1]
(c) The ball reaches its maximum height 40 times in 60 seconds. Calculate the frequency of the
wave.
frequency = ..................................................... Hz [2]
(d) Explain how the motion of the ball shows that the water wave is transverse.
...................................................................................................................................................
. .......................................................................................................................................... [1]
(e) State another example of a transverse wave.
. .......................................................................................................................................... [1]
[Total: 6]
3
(b) Fig. 8.2 represents some wavefronts approaching a barrier with a narrow gap.
barrier
direction of travel
for wavefronts
narrow gap
Fig. 8.2
On Fig. 8.2, draw three wavefronts that have passed through the gap.
[3]
[Total: 4]
Roy and Sally spent time on a beach watching
the incomingwaves. The diagram shows
wavefronts as they approach shallow water. The
waves travel slower in shallow water.
(a)
(b)
(c)
On the diagram, draw an arrow showing
the wave direction and the refracted
wavefronts in the shallowregion.
Clearly explain why the waves behave
as you havedrawn them in the diagram
above.
State what happens to the frequency and
wavelength of the waves as they pass from
deep to shallow water.
4
© UCLES 2020
0972/03/SP/23