GK
BIG BANG THEORY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A fire truck with it’s siren blaring at 7, 000 Hz is traveling towards a stationary observer, Which frequency would the driver of the firetruck hear?
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6, 000 Hz
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7, 000 Hz
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8, 000 Hz
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0 Hz
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Explanation:
Detailed explanation-1: -A sound source with a frequency of 790HZ moves away from a stationary observer at a rate of 15m/s. What frequency does the observer hear? [The speed of sound s 340 m/s.] The answer must be 757 Hz.
Detailed explanation-2: -If a truck approach an observer, the wavefronts emitted by the siren become closer due to the relative motion of the truck. Thus, the observer hears a higher frequency.
There is 1 question to complete.