A stationary police car emits a sound of frequency 1200 Hz that bounces off of a car on the highway and returns with a frequency

Question

A stationary police car emits a sound of frequency 1200 Hz that bounces off of a car on the highway and returns with a frequency of 1280 Hz. The police car is right next to the highway, so the moving car is traveling directly toward or away from it. 
Was the moving car moving towards or away from the police?

Kunduz · Accepted Answer

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