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The ratio of the apparent frequencies of...

The ratio of the apparent frequencies of a car when approaching and receding a stationary observer is 11:9 What is the speed of the car, if the velocity of sound in air is 330 m/s?

Text Solution

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`n'=(300-0)/(300-u)xx1000`
`n''=(300-0)/(300-(-u))xx1000`
dividing
`(n')/(n')=(300+u)/(300-u)`
It is given that `(n')/(n'')=(11)/(9)`, therefore
`(11)/(9)=(300+u)/(300-u)`
or `u=30(m)/(s)`.
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CENGAGE PHYSICS-SOUND WAVES AND DOPPLER EFFECT-Exercise 6.2
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  6. Is there a Doppler effect in the case of sound when the observer or th...

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  7. A source moves away from an obeserver with a certain speed, and the ra...

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  8. An engine blowing a whistle of frequency 133 Hz moves with a velocity ...

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  9. A source of sound of frequency 1000 Hz moves to the right with a speed...

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  10. A stationary source emits sound of frequency upsilon=1200Hz. If a wi...

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  11. A stationary observer receives sound waves from two tuning forks, one ...

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  12. A stationary source sends forth monochromatic sound. A wall approaches...

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  13. A source of sonic oscillations with frequency v(0)=100Hz moves at righ...

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  14. A whistle of frequency 540 Hz rotates in a horizontal circle of radius...

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  15. A bat flies perpendicularly towards a wall with a speed of 6 m/s, emit...

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  16. The ratio of the apparent frequencies of a car when approaching and re...

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  17. A whistle emitting a sound of frequency 440 Hz is tied to string of 1....

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  18. A siren emitting a sound of frequency 2000 Hz moves away from you towa...

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  19. A railroad train is travelling at 30 m/s in still air. The frequency o...

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  20. Two tuning forks A and B having a frequency of 500 Hz each are placed ...

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