**Part a)**

From the Doppler effect:

$\overline{){{\mathbf{f}}}_{{\mathbf{0}}}{\mathbf{=}}\mathbf{\left(}\frac{\mathbf{v}}{\mathbf{v}\mathbf{-}{\mathbf{v}}_{\mathbf{s}}}\mathbf{\right)}{{\mathbf{f}}}_{{\mathbf{s}}}}$

Solving for v_{s}:

$\begin{array}{rcl}\mathbf{v}\mathbf{-}{\mathbf{v}}_{\mathbf{s}}& \mathbf{=}& \frac{{\mathbf{f}}_{\mathbf{s}}}{{\mathbf{f}}_{\mathbf{0}}}\mathbf{v}\\ {\mathbf{v}}_{\mathbf{s}}& \mathbf{=}& \mathbf{v}\mathbf{-}\frac{{\mathbf{f}}_{\mathbf{s}}}{{\mathbf{f}}_{\mathbf{0}}}\mathbf{v}\\ & \mathbf{=}& \mathbf{v}\mathbf{(}\mathbf{1}\mathbf{-}\frac{{\mathbf{f}}_{\mathbf{s}}}{{\mathbf{f}}_{\mathbf{0}}}\mathbf{)}\end{array}$

A student knows that an ambulance siren has a frequency of f_{s} = 396 Hz. He measures, when the ambulance is approaching him, the frequency f_{o} = 417 Hz. Assume the speed of sound is 343 m/s in this problem.

Part a) Input an expression for the ambulance's speed v in terms of the frequencies and the speed of sound v.

Part b) what is this speed, in meters per second

Part c) If ambulance is moving away with the same speed as in part (b) what is the wavelength measured by the student in meters ?

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the The Doppler Effect concept. You can view video lessons to learn The Doppler Effect. Or if you need more The Doppler Effect practice, you can also practice The Doppler Effect practice problems.