“波的图象”是在平面直角坐标系中,用横坐标表示介质中各个质点的平衡位置,用纵坐标表示某一时刻各个质点偏离平衡位置的位移,连接各位移矢量的末端所得到的一条曲线。根据波的图象,可以得到波的振幅、波长;已知波速,可以求出周期和频率;已知传播方向,可以确定该时刻某质点的运动方向,还可以确定一段时间后的波形图等等。由此演变 The “wave image” is a coordinate system in a plane, where the equilibrium position of each particle in the medium is represented by the abscissa, and the displacement of each particle is deviated from the equilibrium position at the time of the ordinate, and the end of each displacement vector is connected. A curve. According to the wave image, the amplitude and wavelength of the wave can be obtained; the known wave speed can be found for the period and frequency; the known propagation direction can determine the motion direction of a certain point at that time, and can also determine the waveform diagram after a period of time, etc. Wait. This evolution