采用干涉法对音叉受迫振动的位移振幅、速度振幅以及音叉振动与外加周期性驱动力的相频关系做了测量与探究. 实验结果表明，位移共振频率与速度共振频率近似相等; 音叉达到共振时，音叉振动与外加周期性驱动力存在π/2 的相位差.利用干涉的方法可对音叉受迫振动的位移振幅、速度振幅以及音叉振动与外加周期性驱动力的相频关系同时进行研究，并且可观测到调节信号源频率至共振频率过程中相位差的改变，以及达到共振时施加外在扰动后相位差偏离π/2 而后恢复的过程.

In this experiment，the character of forced vibration of a tuning fork is studied，including the displacement amplitude，velocity amplitude and phase difference between driving force and vibration. All the charater can be studied at the same time using Michelson interference method. The result shows that the resonance frequency of displacement amplitude and velocity amplitude are approximately equal; there is a π/2 phase difference between driving force and vibration when the resonance is reached. The change of the phase difference when the driving frequency is increased to the resonance can also be observed.