Trumpeter A holds a B-flat note on the trumpet for a long time. Person C is running towards the trumpeter at a constant velocity. Person B is running away from the trumpeter at the same rate. Person D is standing still the whole time.
Which person hears a frequency that is lower than the B-flat?
APerson A
BPerson B
CPerson C
DPerson D
Which person hears a frequency that is lower than the B-flat?
APerson A
BPerson B
CPerson C
DPerson D