physics
posted by carter montgomery .
The siren on an ambulance is emitting a sound whose frequency is 2421 Hz. The speed of sound is 343 m/s. (a) If the ambulance is stationary and you (the "observer") are sitting in a parked car, what are the wavelength and the frequency of the sound you hear? (b) Suppose that the ambulance is moving toward you at a speed of 28.5 m/s. Determine the wavelength and the frequency of the sound you hear. (c) If the ambulance is moving toward you at a speed of 28.5 m/s and you are moving toward it at a speed of 12.6 m/s, find the wavelength and frequency of the sound you hear.

The formula you will need to answer all of these problems can be found at
http://en.wikipedia.org/wiki/Doppler_effect 
456

A. wavelength= 343/ frequency of siren
frequency= 343/ wavelength
B. Frequency= 343* frequency of siren/ (343velocity of ambulance)
wavelength= 343/ frequency you found above
C. Frequency= (343+velocity of your car)*frequency of siren / (343 velocity of ambulance)
wavelength= 343/ frequency you found above