A minivan moving at 38 m/s passes an unmarked state police car moving at 24 m/s. The electromagnetic waves produced by the radar gun in the police car have a frequency of 8.25 × 10⁹ Hz. What is the magnitude of the difference in frequency between the waves emitted by the gun and those that are reflected back from the speeding minivan? A)180 Hz B)390 Hz C)770 Hz D)1440 Hz E)2100 Hz

Question

Quizplus · Accepted Answer

The Doppler effect formula for frequency shift is used here. The frequency shift is calculated using the relative speed of the minivan and the police car, and the speed of light. The correct calculation gives a frequency difference of approximately 770 Hz.

A Minivan Moving at 38 M/s Passes an Unmarked State