# physics

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.

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

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2. 456

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3. A. wavelength= 343/ frequency of siren
frequency= 343/ wavelength

B. Frequency= 343* frequency of siren/ (343-velocity 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

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