2747

Physics Waves And Oscillations Level: High School

Doppler Effect

A truck moving at 36 m/s passes a police car moving 45 m/s headed in the opposite direction . If the frequency of the siren relative to the police car is 500 Hz , what is the frequency heard by an observer in the truck as the police car approaches the truck ? (The truck speed of sound in air is 343 m/s . )