Sound Waves Ex3
1. A television company is making a programme in China. Britain receives television
pictures live from China. The television signals are transmitted using microwaves. The
microwave signals travel from China via a satellite, which is in a geostationary orbit.
a) State what is meant by a geostationary orbit.
(1)
b) The diagram shows the position of the transmitter and receiver. Copy and complete
the diagram to show the path of the microwave signals from China to Britain.
(2)
c) The frequency of the microwave signals being used for transmission is 8 GHz.
(i)
What is the speed of the microwaves?
(1)
(ii)
Calculate the wavelength of these microwaves.
(3)
2. In a sprint race at a school sports day, the runners start when they hear the sound of
the starting pistol. An electronic timer is also started when the pistol is fired into the air.
The runner in lane 1 is 3.2m from the starting pistol. The runner in lane 6 is 10 m from the
starting pistol
a) The runner in lane 1 hears the starting pistol first. Calculate how much later the runner
in lane 6 hears this sound after the runner in lane 1.
(3)
b) A sensor detects each runner crossing the finishing line to record their time.
The table gives information about the race.
Place
1st
2nd
3rd
Lane
1
6
3
Time (s)
13.11
13.12
13.21
Using your answer to part (a), explain why the runner in lane 6 should have been awarded
first place.
(1)
3. A guitar tuner is used to measure the frequency of six guitar strings. The number and
frequency of each string is given in the table below.
Number of
string
1
2
3
4
5
6
Frequency (Hz)
330.0
247.0
196.0
147.0
110.0
82.5
The tuner has an output socket which has been connected to an oscilloscope. The trace for
string 5 is shown in Figure 1.
The controls of the oscilloscope are not altered. Copy Figure 2 into your jotter,
draw the trace obtained if string 1 is played louder than string 5.
(2)
TURN OVER
4. The controls of the signal generator are set up to produce a sound wave from the
loudspeaker. An oscilloscope is now connected across the loudspeaker.
The oscilloscope trace is shown in Figure 1. Copy and complete Figure 2 to show the
trace obtained when the frequency is doubled, but the amplitude remains unchanged.
The oscilloscope controls are unchanged.
(2)