Question

While standing near a bus stop, a student hears a distant horn beeping. The frequency emitted by the horn is 440 Hz. The bus is traveling at 20.0 m/s and the speed of sound is 330 m/s. What frequency will the student hear at each point in the bus' motion?

Answer 1

468 Hz while approaching, 440 Hz through the crossing, 415 Hz while receding
415 Hz while approaching, 440 Hz through the crossing, 468 Hz while receding
440 Hz while approaching, 415 Hz through the crossing, 400 Hz while receding
505hz while approaching, 440hz through the crossing, 438 Hz while receding