A sound source (normal frequency of 1000 Hz) approaches a stationary observer at one-half the speed of sound. The observer hears a frequency of
A) 2000 Hz.
B) 1500 Hz.
C) 500 Hz.
D) 250 Hz.
E) 1414 Hz.

Question

Quizplus · Accepted Answer

When the source approaches the observer at half the speed of sound, the frequency heard by the observer is doubled due to the Doppler effect. Hence, the observer hears 2000 Hz.

A Sound Source (Normal Frequency of 1000 Hz) Approaches a Stationary