Which of the following observations is a result of the Doppler effect?
A)Noise from across a lake is louder at night than during the day
B)A person walking notices that the pitch of a car's engine decreases as the car passes by.
C)Beats are produced when two tuning forks with different frequencies are heard together.
D)A person hears the sound from a radio more clearly in certain areas of a room than in others.

Question

Quizplus · Accepted Answer

The Doppler effect describes the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. Option B is a classic example of the Doppler effect, where the pitch (frequency) of a car's engine sound appears higher as the car approaches and lower as it moves away from the observer. This is due to the sound waves being compressed as the car approaches and stretched as it moves away.

Which of the Following Observations Is a Result of the Doppler