Physics (AS & A Level) · Oct / Nov 2019 · Paper 11 · Question 21

A transverse wave on a rope has wavelength $\lambda$ and period $T$. The graph shows the variation of the displacement of the particles of the rope with distance in the direction of travel of the wave at time $t = 0$. [graph of displacement against distance showing a wave with particle X labelled at a zero-crossing] A particle X is labelled. Which graph shows the variation of the displacement of particle X with time $t$?

1. A[graph: displacement against time, starting at 0 and rising to a positive maximum, crossing zero at T/2]
2. B[graph: displacement against time, starting at a positive maximum, crossing zero, reaching a negative minimum, returning to zero at T]
3. C[graph: displacement against time, starting at 0 and falling to a negative minimum, crossing zero at T/2]
4. D[graph: displacement against time, starting at a negative minimum, crossing zero, reaching a positive maximum, returning to zero at T]

As printed in the paper