Two cars are traveling in the same direction and with the same speed along a straight highway. Does either driver hear a different frequency from the other car's horn than they would if the cars were stationary?
A) Yes, they both experience a Doppler shift.
B) Only the driver of the front car experiences a Doppler shift.
C) Only the driver of the rear car experiences a Doppler shift.
D) No, because neither driver experiences a Doppler shift.
E) It is impossible to predict.

Question

Quizplus · Accepted Answer

Since both cars are traveling with the same speed along the same direction, there is no relative velocity between them. Therefore, neither driver experiences a Doppler shift in the frequency of the other car's horn.

Two Cars Are Traveling in the Same Direction and with the Same