Physics (AS & A Level) · May / June 2017 · Paper 12 · Question 24

A bicycle gear wheel is a disc with 50 'teeth' equally spaced around its edge, as shown. The gear wheel is rotated 10 times each second. A springy strip of metal is vibrated by the rotating 'teeth'. The metal strip produces a sound of frequency that is equal to the frequency of vibration of the strip. The speed of sound in air is 330 m s^-1. What is the wavelength of the emitted sound?

1. A0.66 m
2. B1.5 m
3. C6.6 m
4. D500 m

As printed in the paper