The source of a sound is moving away from an observer who is standing still. How do the sound waves received by the observer compare with those emitted by the source?
A)They are heard as having a greater velocity.
B)They are heard as having a higher frequency.
C)They are heard as having a lower frequency.
D)They are heard as having a smaller wavelength.

Question

Quizplus · Accepted Answer

When a sound source moves away from an observer, the sound waves stretch out, leading to a lower frequency being heard by the observer. This phenomenon is known as the Doppler effect.

The Source of a Sound Is Moving Away from an Observer