A sound wave propagates through air. Fig. 6.1 gives a pressure-time graph for the air at one point. The graph has pressure on the vertical axis, time on the horizontal axis, a straight line marked atmospheric pressure, and a sinusoidal curve that rises above and falls below this line.
(a(i))[2]
On Fig. 6.1:
• put one label C to show a compression
• put one label R to show a rarefaction.
(a(ii))[1]
Explain why this graph cannot be used to determine the wavelength of the sound wave.
(a(iii))[1]
State what happens to:
• the amplitude of the sound
• the frequency of the sound.
(b)[3]
Calculate the wavelength of this sound in water.
(c)[1]
State the approximate speed of sound in air.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “C placed at the peak of the sine wave” …