Question

which of the following are true about the listeners perception of sound in relation to the doppler effect? select all that apply a as a car speeds away from a listener, the sound waves get farther apart, decreasing their frequency and the pitch of the sound. b the listener will not notice any change in the pitch of the sound as the car approaches or moves away. c the listener will hear a higher pitch as the car moves away. d as a car approaches a listener, the sound waves get closer together, increasing their frequency and the pitch of the sound. e the listener will hear a lower pitch as the car approaches.

Explanation:

The Doppler Effect describes how the frequency of waves (such as sound) changes for an observer when the source of the waves is moving relative to the observer. When a car (source of sound) moves away from a listener (observer), the sound waves are stretched (get farther apart), which decreases the frequency and pitch (so option a is correct). When the car approaches, the sound waves are compressed (get closer together), increasing the frequency and pitch (so option d is correct). Options b, c, and e are incorrect as they do not align with the principles of the Doppler Effect.

Answer:

A. As a car speeds away from a listener, the sound waves get farther apart, decreasing their frequency and the pitch of the sound.
D. As a car approaches a listener, the sound waves get closer together, increasing their frequency and the pitch of the sound.