Question

A train is moving parallel and adjacent to a highway with a constant speed of 31 m/s. A car is traveling in the same direction as the train at 55 m/s. The train’s whistle sounds at 330 Hz. When the car is behind the train what frequency does an occupant of the car observe for the train whistle? The speed of sound is 343 m/s. Answer in units of Hz.

Answer 1

source velocity V_s=31m/s

observer velocity V_o=55m/s

frequency is n=330Hz

Velocity is v=343m/s

frequency obseved by the observern¹=[(v+v_o)/(v+v_s)]*n

                                                        =[(343+55)/(343+31)]*330

                                                         =351.17Hz