A source emits sound at a fixed constant frequency f . If you run towards the source, the frequency you hear is
A) the same as f.
B) higher than f.
C) lower than f.
D) unrelated to f.

Question

Quizplus · Accepted Answer

When running towards the source, you are approaching the sound waves being emitted. Therefore, the relative velocity between you and the waves increases, causing the wavelength to decrease and the frequency to increase (according to the equation v=fλ, where v is the speed of sound). This means that the frequency you hear will be higher than the original frequency f.

A Source Emits Sound at a Fixed Constant Frequency F