Wave Motion Displacement (y): Position of an oscillating particle from its equilibrium position. Amplitude (y 0 or A): The maximum magnitude of the displacement of an oscillating particle from its equilibrium position. Period (T): Time taken for a particle to undergo one complete cycle of oscillation. Frequency (f): Number of oscillations performed by a particle per unit time. Wavelength (λ): For a progressive wave, it is the distance between any two successive particles that are in phase , e.g. it is the distance between 2 consecutive crests or 2 troughs. Wave speed (v): The speed at which the waveform travels in the direction of the propagation of the wave. Wave front: A line or surface joining points which are at the same state of oscillation, i.e. in phase, e.g. a line joining crest to crest in a wave. Ray: The path taken by the wave. This is used to indicate the direction of wave ...