If a source of sound is moving, a stationary listener will hear a sound of different frequency. This is called

khadijatkyekeen

1 year ago

correct. The Doppler effect in sound waves is the change in the frequency or pitch of a sound that you hear when the source of the sound or the observer (or both) is moving relative to each other.

Explanation:
When the sound source is moving toward the observer, the sound waves get compressed, leading to a higher frequency and a higher pitch (the sound seems "shriller").
When the sound source is moving away from the observer, the sound waves stretch out, leading to a lower frequency and a lower pitch (the sound seems "deeper").
Everyday Examples:
Moving Ambulance Siren:
When an ambulance approaches, the siren sounds higher-pitched.
As it moves away, the pitch becomes lower.
Train Whistle:
The sound of a train's whistle changes as it moves past you.