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Question
A pebble is dropped freely in a well from its top. It takes 20 s for the pebble to reach the water surface in the well. Taking g = 10 m s-2 and speed of sound = 330 m s-1. Find : The depth of water surface
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Solution
Time t =20 s
g = 10 m/s2
Let 'D' be the depth of the well.
Using the second equation of motion,
D = ut + (1/2) gt2
D = 0 + (1/2)(10)(20) 2
D = 2000 m
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