Assume that the pitch of a honking car horn is the F above middle C (f F= 349 Hz) and the speed of sound in air
is 770 mph. How fast would a honking car need to be approaching you for you to hear a G (fG = 392) instead of
an F?
Fr = ((Vs+Vr)/(Vs-Vc))*Fc = 392 Hz.
((770+0)/(770-Vc))*349 = 392
((770)/(770-Vc))*349 = 392
268,730/(770-Vc) = 392
301,840 - 392Vc = 268,730
-392Vc = -33,110
Vc = 84.5 mi/h = Velocity of the car.
Vs = Speed of sound in air.
Vr = Velocity of the receiver(hearer) of the sound.