At any point along the path of the wave, a repeated displacement, or oscillation, occurs. In each case the particles of matter oscillate around a neutral position, and only the energy moves continuously in one direction. Types of Waves Waves are classified according to the direction of the particle displacements in relation to the direction that the wave itself moves. Sound waves are longitudinal. If the displacement and the wave move at right angles to each other, the wave is transverse.
Ocean waves are transverse.
The wavelength of transverse waves is the distance between two crests or troughs. The wavelength of longitudinal waves is the distance from compression to compression or from rarefaction to rarefaction. The frequency is the number of displacements per second, and the velocity of the wave, the speed at which it advances, is equal to the wavelength times the frequency. The maximum displacement is the amplitude of the wave. The velocity of a mechanical wave depends on the elasticity and density of the material in which it moves.