A car with its horn sounding approaches a group of students. Assume the car's horn produces sound waves with a constant frequency.Which of the following statements bestexplains why the students hear a higher pitch as the car approaches than when it is stopped?
A)The sound waves increase in speed as the car approaches the students.
B)The sound waves decrease in speed as the car approaches the students.
C)The sound waves are heard at a lower frequency as the car approaches the students.
D)The sound waves are heard at a higher frequency as the car approaches the students.

Question

Quizplus · Accepted Answer

This phenomenon is explained by the Doppler effect, which states that the frequency of a wave increases for an observer towards whom the source of the wave is moving. As the car approaches, the sound waves are compressed, leading to a higher frequency heard by the students.

A Car with Its Horn Sounding Approaches a Group of Students