An oscillator tuned to a frequency of 1 kHz is dropped from a tall building.How does the frequency picked up by a stationary observer at the top of the building change with time?
A)The frequency will be lower than 1 kHz but does not change with time.
B)The frequency will be lower than 1 kHz and decreases further with time.
C)The frequency will be higher than 1 kHz but does not change with time.
D)The frequency will be higher than 1 kHz and decreases further with time.
E)The frequency stays at 1 kHz.

Question

Quizplus · Accepted Answer

As the oscillator falls, it experiences a change in frequency due to the Doppler effect. The frequency picked up by a stationary observer at the top of the building is lower than 1 kHz because the oscillator is moving away from the observer. As the oscillator falls further, the frequency picked up by the observer decreases further due to the Doppler effect. Therefore, the correct answer is B.

An Oscillator Tuned to a Frequency of 1 KHz Is