Определение periodic motion в Английский Язык Английский Язык словарь
motion that recurs over and over and the period of time required for each recurrence remains the same
Motion that is repeated in equal intervals of time. The time of each interval is the period. Examples of periodic motion include a rocking chair, a bouncing ball, a vibrating guitar string, a swinging pendulum, and a water wave. See also simple harmonic motion