A sound source departs from a stationary observer. The frequency heard by the observer is
A) higher than the source.
B) lower than the source.
C) the same as that of the source.
D) equal to zero.
E) impossible to predict.

Question

Quizplus · Accepted Answer

When a sound source departs from a stationary observer, the frequency heard by the observer is lower than the source. This is because the waves are stretched out as they move away from the observer, causing the wavelength to increase and the frequency to decrease. This phenomenon is known as the Doppler effect.

A Sound Source Departs from a Stationary Observer