Mechanical Waves Unit Vocabulary Mechanical wave: wave consisting of periodic motion of matter. Transverse wave: wave in which disturbance is perpendicular to direction of traveling wave. Longitudinal wave: wave in which direction of disturbance is the same as the direction of travel of wave. Surface wave: wave on surface of liquid with characteristics of both longitudinal and transverse waves. Wave pulse: single disturbance moving through a medium or field. Traveling wave: moving, periodic disturbance in a medium or field. Periodic wave: a wave whose medium disturbance displacement has a periodic variation with time or distance, or both. wavelength: distance between corresponding points of two successive waves. Crests (crest of wave): high point of wave motion or maximum positive direction displacement position of a medium experiencing a wave traveling through it. Troughs (trough of wave): low point of wave motion, where displacement is most negative or maximum negative direction displacement position of a medium experiencing a wave traveling through it. Interference (interference of waves): displacements of two or more waves, producing either larger or smaller waves. Principle of super position : the displacement due to two or more forces is equal to vector sum of forces. Constructive Interference: superposition of waves resulting in a combined wave with amplitude larger than the component waves. Destructive Interference: superposition of waves resulting in a combined wave with amplitude equaling the zero or the resulting amplitude being lower than either of the component waves. Node: point where disturbances caused by two or more waves results in no medium displacement. Antinode: point of maximum displacement of two or more superimposed waves. Standing wave: superimposed wave resulting that has stationary nodes and antinodes; it is the result of identical waves traveling in opposite directions.