Compute each part of given question:

Question: The siren on an ambulance is emitting a sound whose frequency is 2850 Hz. The speed of sound is 343 m/s.

Part 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?

Part B: Suppose that the ambulance is moving toward you at a speed of 26.7 m/s. Determine the wavelength and the frequency of the sound you hear.

Part C: If the ambulance is moving toward you at a speed of 26.7 m/s and you are moving toward it at a speed of 16.0 m/s, find the wavelength and frequency of the sound you hear.

Please use as much detail as required in answer for above question. Thanks.