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Question
How much is the mass of a man if he has to do 2500 joules of work in climbing a tree 5 m tall? (g = 10 m s−2)
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Solution
Work done in climbing or potential energy, (P.E) = 2500 J
Acceleration due to gravity, (g) = 10 m/s2
Height above the ground be, (h) = 5 m
Let the mass of the man be (m)
We have a relation as,
P.E = m × g × h
So, mass can be calculated as,
`m = (P.E)/(h xx g)`
so , mass of the man ,
`m = 2500/(5 xx 10)` kg
= `250/5` kg
= 50 kg
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