Physics
A body of mass 10 kg falls from a height of 20 m to 8 m.
Calculate:
(i) the loss in potential energy of the body,
(ii) the total energy possessed by the body at any instant? (Take g = 10 ms-2).
Answer
Given,
Mass = 10Kg
Fall in height = 20 - 8 = 12m
(i) Loss in potential energy = mg(h1 - h2)
Substituting the vales in formula we get,
Loss in potential energy = 10 x 10 x 12 = 1200 J
(ii) Total energy remains constant for free fall.
Total energy = P.E + K.E
So, at height 20 m, K.E = 0
Therefore total energy = P.E + K.E
Total energy = mgh + 0
= 10 x 10 x 20 = 2000 J
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