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Alona [7]
2 years ago
9

A police car travels towards a stationary observer at a speed of 15m/s. the siren on the car emits a sound of frequency 250Hz. C

alculate the observer frequency. the speed of sound is 340m/s​
Physics
1 answer:
skelet666 [1.2K]2 years ago
7 0

Observer Frequency = sound frequency x ( speed of sound / speed of sound - speed of car)

= 250 x (340/( 340-15))

= 261.54 Hz

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Velocity = displacement (distance)/time

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v=20m/s

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What is an odometer?
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Answer:

Time taken, T=2\pi \sqrt{\dfrac{l\ cos\theta}{g}}

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Equation (1) becomes :

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Put the value of T from equation (2) to the above expression:

T=\dfrac{2\pi r}{\sqrt{gl\ tan\theta.sin\theta}}

T=\dfrac{2\pi l\ sin\theta}{\sqrt{gl\ tan\theta.sin\theta}}

On solving above equation :

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Answer:

Explanation:

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substitute the value in the equation above

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Hence, the change in combine kinetic energy is -2534.78J

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