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A bolt of mass 0.3 kg falls from the cei...

A bolt of mass `0.3 kg` falls from the ceiling of an elevator moving down with an uniform speed of `7 ms^(-1)`. It hits the floor of the elevator (length of the elevator = 3m) and does not rebound. What is the heat produced by the impact? Would your answer be different if the elevator were stationary?

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Mass of bolt m = 0.3 kg
Height at which bolt is stay h = 3 m
If bolt hits the floor and does not rebound , its potential energy decreases ,
`Delta V = mgh `
` = 0.3 xx9.8 xx3 = 8.82 J `
Heat energy produced = Decreases in potential energy = 8.82 J
Because here kinetic energy cannot increases.
If elevator is stationary or moving with constant speed this answer will be true because there is no relation between the motion of elevator and the potential energy of bolt .
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