Question

with regard to the observer shown in the model? a the volume will decrease because the train is moving away. the pitch will be lower because the frequency of the sound waves is decreasing. b the volume will decrease because the train is moving away. the pitch will be higher because the frequency of the sound waves is increasing. c the volume will increase because the train is moving away. the pitch will be higher because the frequency of the sound waves is increasing. d the volume will decrease because the train is moving away. the pitch will remain the same because there is no shift in the frequency of the sound waves.

Explanation:

The Doppler - effect for sound states that when a source (the train) moves away from an observer, the distance between successive sound - wave crests increases, causing a decrease in frequency (lower pitch). Also, as the source moves away, the intensity of the sound (volume) decreases due to the spreading of sound energy over a larger area.

Answer:

A. The volume will decrease because the train is moving away. The pitch will be lower because the frequency of the sound waves is decreasing.