Question

Why does the Doppler effect occur when the source of sound is stationary, and the listener is in motion

A. Because the stationary source emits waves with varying frequencies
B. Because the listener's motion affects the speed of sound waves
C. Because the motion of the listener changes the effective distance between the source and the observer
D. Because the stationary source causes a compression of sound waves

Answer 1

The Doppler effect occurs when the listener is in motion and the source of sound is stationary. The motion of the listener changes the effective distance between the source and the observer, resulting in a change in frequency and pitch of the sound waves received by the listener.

Step-by-step explanation:

The Doppler effect occurs when the source of sound is stationary, and the listener is in motion because the motion of the listener changes the effective distance between the source and the observer.

When the listener is moving towards the stationary source, the wavelength of the sound waves becomes shorter, causing an increase in frequency and a higher pitch. Conversely, when the listener is moving away from the stationary source, the wavelength becomes longer, causing a decrease in frequency and a lower pitch.

For example, if you are standing still and a car with a siren drives towards you, you will hear the pitch of the siren increase as the car gets closer, and then decrease as it moves away.