train moving with speed 72 km h−1

Question

emits a whistle of frequency 600 Hz. A
person is standing stationary on the platform. Calculate the frequency heard by the
person if the train (i) approaches and (ii) recedes away from the listener.

Answer 1

Vt = 72,000m/h * 1h/3600s = 20 m/s.

a. Fp = (Vs+Vp)/(Vs-Vt) * Ft =(343+0)/(343-20) * 600 = 637.2 Hz.

b. Fp = (Vs-Vp)/(Vs+Vt) * Ft =