Physics (AS & A Level) · Oct / Nov 2016 · Paper 11 · Question 25

The graph shows the variation with time of the displacement X of a gas molecule as a continuous sound wave passes through a gas. The velocity of sound in the gas is 330 m s⁻¹. All the graphs below have the same zero time as the graph above. What is the displacement-time graph for a molecule that is a distance of 0.165 m further away from the source of the sound?

1. AGraph A: displacement-time graph starting at maximum positive displacement at t = 0, with period 500 µs
2. BGraph B: displacement-time graph starting at zero displacement with negative gradient at t = 0, with period 500 µs
3. CGraph C: displacement-time graph starting at maximum negative displacement at t = 0, with period 500 µs
4. DGraph D: displacement-time graph starting at zero displacement with positive gradient at t = 0, with period 500 µs

As printed in the paper