With what velocity should an observer approach a stationary sound source, so that the apparent frequency of sound should appear double the actual frequency? ( v is velocity of sound).

Step-by-step solution

Given, sound source is stationary, v_ S =0 Apparent frequency, f^ =2 f where, f is actual frequency of sound. By using Doppler's effect, aligned f^ &=f ( v+v₀ v ) & [ where, v is velocity of sound A .] 2 f &=f ( v+v₀ v ) 2 v &=v+v₀ v₀ &=v aligned