Mechanical waves must travel through a medium A periodic wave is a wave that repeats for several cycles, whereas a pulse wave has only one crest or a few crests and is associated with a sudden disturbance

A transverse wave has a disturbance perpendicular to its direction of propagation, whereas a longitudinal wave has a disturbance parallel to its direction of propagation Sound waves, water waves, and earthquake waves are all examples of mechanical waves

wave — disturbance that moves from its source and carries energy. periodic wave — wave that repeats the same oscillation for several cycles and is associated with simple harmonic motion. transverse wave — wave in which the disturbance is perpendicular to the direction of propagation. longitudinal wave — wave in which the disturbance is parallel to the direction of propagation.