(a)[3]
Produce a sketch of a longitudinal wave. On the sketch, label a distance to represent the wavelength, and mark and label the centre of one compression and the centre of one rarefaction.
(b(i))[1]
State what happens to the frequency of the wave.
(b(ii))[1]
State what happens to the wavelength of the wave.
(c)[1]
State a typical value for the speed of sound in air.