A source emits sound with a frequency of 1000 Hz. Both it and an observer are moving in the same direction with the same speed, 100 m/s. If the speed of sound is 340 m/s, the observer hears sound with a frequency of:
A) 294 Hz
B) 545 Hz
C) 1000 Hz
D) 1830 Hz
E) 3400 Hz

Question

Quizplus · Accepted Answer

Since both the source and the observer are moving at the same speed in the same direction, there is no relative motion between them. Therefore, the observer hears the sound at the same frequency as emitted, which is 1000 Hz.

A Source Emits Sound with a Frequency of 1000 Hz