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

In an experiment with water waves in a ripple tank, a variable frequency a.c. source was used to vibrate a dipper to produce ripples. The wavelength, λ, and wave speed, v, of the ripples were measured for various dipper frequencies. The graph in Figure 5(b) shows the variation of wave speed, v, with wavelength, λ, for ripples up to a wavelength of 8 mm.

By how much does the frequency decrease when the wavelength is changed from 3 mm to 8 mm?

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