The siren on a police van is emitting a sound whose frequency is 2493 Hz. The speed of sound is 343 m/s.
(a) If the police van is stationary and you (the "observer") are sitting in a parked car, find the wavelength and the frequency of the sound you hear?
(b) Assume that the police van is moving toward you at a speed of 28.7 m/s. Compute the frequency and the wavelength of the sound you hear.
(c) If the police van is moving toward you at a speed of 28.7 m/s and you are moving toward it at a speed of 12.7 m/s, determine the frequency and wavelength of the sound you hear.