Question

Person A holds a note on the trumpet for a long time. He points the trumpet directly in front of him and not to either side. Person C is

running towards Person A at a constant speed. Person B is running away from Person A at the same rate. Person D is standing still the
whole time. Which person hears a frequency that is LOWER than the note that Person A is playing?
a. Person D
b. Person C
c. Person B

Answer 1

Person B hears a frequency that is lower than the note Person A is playing, as a result of the Doppler Effect caused by Person B moving away from the source of the sound.

Step-by-step explanation:

The question pertains to the Doppler Effect, which describes the change in frequency of a wave in relation to an observer who is moving relative to the wave source. In this scenario, Person C is running towards the trumpet player (Person A) and would hear a higher frequency than the note being played due to the compression of sound waves. Similarly, Person B is running away from Person A and would hear a lower frequency because the sound waves are stretched as they move away from the sound source. Person D, who is standing still, would hear the frequency as it is being played by Person A, without any Doppler shift.