A progressive wave of frequency 500Hz is travelling with a velocity of 360 m`//` s. How far part are two points `60^(@)` out of phase ?

Explanation

We know that for a wave `v=f lamda` So `lamda = (v)/(f)=(360)/(500)=0.72m`
Phase difference `Deltaphi=60^(@)=(pi//180)xx60=(pi//3)` rad, so path difference `Delta x=(lamda)/(2pi)(Deltaphi)=(0.72)/(2pi)xx(pi)/(3)=0.12 m`.