机械纵波的观察与波速测量实验的设计构思

A Designed Experiment for Observation and Wave Velocity Measurement of Mechanical Vertical Wave

为了进一步丰富大学物理实验课的教学内容,针对机械波特别是机械纵波实验较少的情况,我们设计了一种一维弹性介质链来演示机械纵波在弹性介质中的产生和传播过程,并验证机械波波速与频率无关,只决定于介质的性质。具体为采用轻质小弹簧连接的塑料小球链模拟质元之间的弹性力和一维弹性介质质元,采用带电小球在交变电场作用下的振动模拟波源的办法,设计了一个可观察机械纵波并测量波速的实验。这个实验既可以作为大学物理实验课的教学内容,也可以作为中学物理实验的演示实验,有助于学生直观形象地理解机械波的产生和机械波在弹性介质中的传播机理。

There is few the experiment project of mechanical vertical wave in present physics experiment teaching.In order to further enrich the teaching content of college physics experiment course,we designed a one-dimensional elastic medium chain experiment which demonstrated the generation and propagation of mechanical wave in elastic medium,and verified that mechanical wave velocity is independent of frequency,it only depends on the nature of the medium.Here,the chain,which is made up of plastic balls connected by light springs,simulates the elastic force between mass elements and the one-dimensional elastic medium element.The wave source was simulated by the vibration of charged ball under alternating electric field.The experiment is designed to observe vertical wave and measure wave velocity.The experiment can be the teaching content of physics experiment course in colleges and the lecture experiment in middle schools,which contributes students to understand intuitively the formation of mechanical wave and mechanism of transmission in elastic medium.