Question
A skydiver falls in air reaching terminal velocity, he shouts to his friend at 2000 Hz. His friend receives it at 2355 Hz, what is the divers speed?
Answers
Henry
F = ((Vs+Vr)/(Vs-Vd))*Fd = 2355 Hz.
((343+0)/(343-Vd))*2000 = 2355
((343)/(343-Vd))*2000 = 2355
686000/(343-Vd) = 2355
2355(343-Vd) = 686000
343-Vd = 291.3
-Vd = 291.3-343 = -51.7
Vd = 51.7 m/s = Velocity of the diver.
((343+0)/(343-Vd))*2000 = 2355
((343)/(343-Vd))*2000 = 2355
686000/(343-Vd) = 2355
2355(343-Vd) = 686000
343-Vd = 291.3
-Vd = 291.3-343 = -51.7
Vd = 51.7 m/s = Velocity of the diver.