Question

A Loyola bus going southbound at 25.0 m/s on Lake Shore Drive (LSD) near the Irving Park exit, notices CPD behind them with lights flashing and siren blaring. The police are going 40.0 m/s and are using a siren that operates at f = 1000.0 Hz. Assume the speed of sound at this stretch of LSD is 340.0 m/s. The bus driver pulls over to stop while CPD continues past without changing speed. QUESTION calls for two frequencies: What frequency did the bus passengers hear when the bus was in front of the police car, and after they have stopped?

Answer 1