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Question
A man raises a box of mass 50 kg to a height of 2 m in 20s, while another man raises the same box to the same height in 50s. Calculated:
- the work done, and
- the power developed by each man. Take g = 10 N kg-1.
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Solution
(i) Work done by each man = mgh
= 50 × 10 × 2
= 1000 J
(ii) Work done in first case = `w/t_1`
= `1000/20`
= 50 W
Work done in second case = `w/t_2`
= `1000/50`
= 20 W
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