Chapter 13 wave motion and sound 早周期T:波前进一个波长的距离所需要的时 a]. Period is the time required for one complete oscillation or one complete cycle of the wave to pass a given point along the line of travel 频率∫:周期的倒数,即单位时间内波动所 传播的完整波的数目. The frequency is the number of crests-or complete cycles-that pass a given point per unit time. f=1/ 振幅 Amplitude D: it is the maximum displacement of the elements from their equilibrium positions as the wave passes through them. The height of crest or the depth of a trough.Chapter 13 Wave Motion and Sound  周期 ：波前进一个波长的距离所需要的时 间. Period is the time required for one complete oscillation or one complete cycle of the wave to pass a given point along the line of travel. T f =1 T  频率f ：周期的倒数，即单位时间内波动所 传播的完整波的数目. The frequency is the number of crests—or complete cycles-that pass a given point per unit time.  振 幅 Amplitude Dm : it is the maximum displacement of the elements from their equilibrium positions as the wave passes through them. The height of crest or the depth of a trough