Question

A speaker has frequency `120` Hz while two points along the horizontal (x) axis register a phase difference of `3` rad, what is the distance of these two points in meters?

Answer 1

Path difference(`dx`) and phase difference(`d phi`) are related as,

`d phi = (2pi)/lambda * d x`

Now,if velocity(`c`) of sound is `343 m/s`,and frequency(`nu`) is `120 Hz`,

using `c= nu lambda` , `lambda =2.858 m`

Given `d phi =3 rad`

So, `dx = 1.36 m`