Physics · May / June 2021 · Paper 11 · Question 20

A water wave in a ripple tank refracts as it moves from deep water into shallower water. [diagram: deep water and shallower water with wavefronts and ray] What happens to the speed and to the frequency of the wave as it moves into shallower water?

1. Aspeed decreases, frequency stays constant
2. Bspeed increases, frequency stays constant
3. Cspeed stays constant, frequency decreases
4. Dspeed stays constant, frequency increases

As printed in the paper