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At an air show a jet flies directly toward the stands at a speed of 1230 km/h, emitting a frequency of 3140 Hz, on a day when the speed of s
Question
At an air show a jet flies directly toward the stands at a speed of 1230 km/h, emitting a frequency of 3140 Hz, on a day when the speed of sound is 342 m/s.
a. What frequency (in Hz) is received by the observers?
b. What frequency do they receive as the plane flies directly away from them?
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Physics
6 months
2021-07-29T23:46:16+00:00
2021-07-29T23:46:16+00:00 2 Answers
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Answers ( )
Explanation:
Given that,
Speed of the jet,
Frequency of the sound produced by jet, f = 3140 Hz
Speed of sound in air, v = 342 m/s
(a) The formula of the observed frequency is given in terms of Doppler’s effect as :
(b) Let f’ is the frequency received as the plane flies directly away from them. So,
Hence, this is the required solution.
Answer:
a.
b.
which won’t be audible to the humans as the audible capacity of the human ear is from 20 Hz to 20,000 Hz.
Explanation:
Given:
a.
Since the sound source is moving therefore we can determine the observed frequency by the Doppler’s effect given as:
where:
b.
When the plane flies away from the observers then we take its velocity as negative.
where: