在高中物理受迫振动这一节内容中，有一个演示实验，器材如图１。当摇动曲轴时，下端的砝码随之作上下周期性往复运动，用来说明受迫振动和共振现象（策动力频率和物体的固有频率间的关系）。教师在操作过程中普遍反映效果不够理想：①在运动过程中，下面的砝码经常出现水平方? In the section on physical forced vibration in high schools, there is a demonstration experiment. The equipment is shown in Figure 1. When the crankshaft is shaken, the weight at the lower end performs periodic up and down reciprocating motions to illustrate the relationship between forced vibration and resonance (the relationship between the natural frequency of the steering power frequency and the object). In the course of operation, teachers generally reflect the effect is not ideal: 1 in the course of the movement, the following weight often appear horizontal?