Physics (AS & A Level) · Oct / Nov 2016 · Paper 13 · 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: cosine-like curve starting at maximum displacement at t = 0
2. BGraph B: sine-like curve starting at zero displacement, initially negative
3. CGraph C: sine-like curve starting at zero displacement, initially positive
4. DGraph D: sine-like curve starting at zero displacement, initially positive, same as original graph

As printed in the paper