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Question
An echo returned in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 m s−1?
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Solution
Speed of sound, v = 342 m s−1
Echo returns in time, t = 3 s
Distance travelled by sound = v × t
= 342 × 3
= 1026 m
In the given time interval, sound has to travel a distance that is twice the distance of the reflecting surface and the source.
Hence, the distance of the reflecting surface from the source is = `1026/2` m
= 513 m
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Numerical problems:
An echo returned in 3s. What is the distance of the reflecting surface from the source given that the speed of sound is 330 ms-1?
