学习“机械波”一章后,在根据质点的振动方向判断波的传播方向时,学生普遍感到困难.现以一题为例,介绍四种简单判别方法,以供参考. 例一列横波在某时刻波形图线如图1所示,此时刻质点p振动方向向上,试判断该波的传播方向.方法1 波源位置法方法要点:质点间存在相互作用力,距波源近的点带动后一点振动,即后一点振动比前一点滞后,从而振动形式逐渐传播开去. After learning the chapter on “mechanical waves”, students generally feel difficulties in determining the direction of wave propagation based on the vibration direction of the particles. Now, taking an example as an example, four simple identification methods are introduced for reference. Example A transverse wave at a certain moment The waveform line is shown in Fig. 1. At this moment, the vibration direction of particle p is upward, and the direction of wave propagation is tested. Method 1 The method of wave source position method: There is interaction force between particles, and the vibration is caused by the point near the wave source. That is, the latter point of vibration lags behind the previous point, so that the vibration form gradually spreads.