# A stone is dropped into a well of depth 67.6 m. The splash of water is heard..........Find the velocity of sound in m/s?

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A stone is dropped into a well of depth 67.6 m.
The splash of water is heard after 3.91 seconds.
Find the velocity of sound in m/s?

posted Nov 7, 2019

S=ut+1/2gt^2
67.6=0*t+1/2*9.8*t^2 --> t= sqrt (676/49)=26/7 =3.71 sec - time the stone takes to touch the water
Time taken by sound to reach surface = 3.91–3.71=0.2 sec
Speed of sound = 67.6/0.2 m/sec= 338 m/sec

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