Question

If a car whose horn emits a frequency of 500 Hz is driving toward you at 30 m/s, which frequency might be the one that you hear?

Answer 1

F = (Vs+Vo)/(Vs-Vh) * Fh.
F = (343+0)/(343-30) * 500 =

Vs = velocity of sound.
Vo = velocity of the observer.
Vh = velocity of the horn.

Answer 2

550hz

Answer 3

550 hz