Question

A wave of frequency $500Hz$ has a wave velocity of $350m/s$. Find the phase difference in degrees between two displacements at a certain point at times ${10}^{-3}$ s apart.

Answer 1

The phase difference , $\Delta \varphi =k\Delta x$
where $k=\frac{2\pi }{\lambda }=\frac{2\pi f}{v}$, wave number and $\Delta x=vt$, path difference.
thus, $\Delta \varphi =\frac{2\pi f}{v}.vt=2\pi ft=2\pi \left(500\right)\left({10}^{-3}\right)=\pi ={180}^o$