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Question
A man stands in between two parallel cliffs and blows a whistle. He hears first echo after 0.6s and second echo after 2.4s. Calculate the distance between cliffs.
[Speed of sound = 336 m/s]
Solution
Given: t1 = Time after which first echo is heard = 0.6s
t2 = Time after which second echo is heard = 2.4s
v = Velocity of sound = 336 m/s.
For an echo the distance travelled by the sound is 2d.
d1 = `("v"xx"t"_1)/2`
Or, d1 = `(336xx0.6)/2` = 100.8 m
And d2 = `("v"xx"t"_2)/2`
Or, d2 = `(336xx2.4)/2` = 403.2 m
∴ Total distance between two cliffs
= d1 + d2 = (100.8 + 403.2)m = 504 m.
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