CAPE Physics Unit 1 · 2008 · Paper 2 · Question 5(a)

A piece of perspex is placed in a ripple tank to make the water shallower, as shown in Figure 5(a). As waves cross the front of the perspex, which is at an angle θ to the direction of propagation, they slow down.

With the aid of a diagram, explain what happens to the waves. What is this phenomenon called?

This question uses a figure or table from the paper — you'll see it when you practise.