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Question
The gravitational potential energy stored in a box of weight 150 kgf is 1.5 × 104 J. Find the height of the box. Take 1 kgf = 10 N.
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Solution
Gravitational potential energy (U) = 1.5 × 104 J
Force = weight = 150 kgf = 1500 N ...[1 kgf = 10 N]
Height (h) = ?
U = mg × h
∴ 1.5 × 104 J = 1500 × h
∴ `(1.5 × 10^4 " J")/(1500)` = h
∴ h = 10 m
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