居家实验:硬币弹跳

HOME EXPERIMENT——COIN BOUNCING

本文给出了居家环境下基于智能手机研究硬币弹跳的声学频率和产生的共振模式一种方案。理论上首先根据圆板的振动方程,给出了硬币固有振动频率的表达式。之后结合特定边界条件,利用有限元的方法分析了三种类型硬币的固有振动模式及对应频率。实验上利用智能手机测量了不同硬币在自由振动时产生的声音频率,并与模拟计算结果进行比较,给出了合理的误差分析。该居家实验方案简单有趣,物理原理丰富,易于在基础物理实验教学中推广。

In this paper,the smart phone was used to study the acoustic frequency and resonance mode of coin bouncing in home environment.Firstly,according to the vibration equation of the circular plate,the expression of the natural vibration frequency of the coin is given.Then combined with specific boundary conditions,the natural vibration modes and corresponding frequencies of three types of coins are analyzed by finite element method.In the experiment,the acoustic frequency produced by the free vibration of different coins is measured by smart phone,and compared with the simulation results,then a reasonable error analysis is given.This home experiment scheme is rich in physical principles,simple and interesting,and easy to be popularized in basic physics experiment teaching.