The diagram shows a transverse wave.

Which letter represents the wavelength of the wave?
A marine research buoy registers 52 complete oscillations of ocean surface waves over a period of 80 seconds. Calculate the frequency of these waves and state the unit.
Primary (P) seismic waves are longitudinal waves. State one other type of wave that is longitudinal.
Compare transverse and longitudinal waves by describing the relationship between the direction of oscillation and the direction of wave energy transfer for each wave type.