Question

Imagine that a listener who is at rest is listening to the sound of frequency $20Hz$ produced by a stationary source. If the source starts moving away from the listener, will the listener be able to hear the sound? Justify your answer.

Answer 1

When the source of the sound moves away from the listener, the waves behind the source appear to be further apart. The wavelength increases. Therefore he feels pitch of the sound to be lower.Hence listener will be able to hear the sound of lower pitch.