A NASCAR racing car has an engine that produces engine noise with a frequency of2500 Hz when it is at rest in its garage. The car is leaving pit row and traveling at 90 m/s as it reenters the race. Benjamin is standing at the side of the road holding the finishing flag. Assume that the speed of sound in air is 343 m/s.
A) Calculate the frequency of the engine noise that Benjamin hears as the car approaches him.
B) After the car passes him, calculate the change in frequency of the engine noise that Benjamin hears.