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bonufazy [111]
3 years ago
13

The driver of a stationary car hears a siren of an approaching police car at a frequency of 280Hz. If the actual frequency of th

e siren is 240Hz, find the speed of the police car (speed of sound is 343m/s).
Physics
1 answer:
deff fn [24]3 years ago
5 0

Answer:

The speed of the police car is 294 m/s

Explanation:

Given;

frequency of the siren in air, f = 280 Hz

speed of sound in air, v = 343 m/s

Determine the wavelength of the sound in air to the stationary car:

v = fλ

where;

λ is wavelength of the sound

λ = v/f

λ = 343 / 280

λ = 1.225 m

Now, determine the speed at which the police car is approaching the stationary car;

The actual frequency of the police car, F = 240 Hz

V = Fλ

Where;

V is speed of the police car

λ is the distance between the police car and the stationary car, (wavelength)

V = 240 x 1.225

V = 294 m/s

Therefore, the speed of the police car is 294 m/s

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