Question

question 20 of 33
the whistle on a train produces a sound wave with a particular pitch. which of the following best describes the whistle sound that a person perceives as the train approaches and then passes him or her?
a. the same pitch
b. a lower pitch
c. a higher pitch, then a lower pitch
d. a higher pitch

Explanation:

This is related to the Doppler - effect in physics. When the train approaches, the sound waves are compressed, resulting in a higher - pitched sound. When the train passes and moves away, the sound waves are stretched, leading to a lower - pitched sound.

Answer:

C. A higher pitch, then a lower pitch