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Question
Calculate the amount of work done by a child carrying a bag of 20 kg when he moves a distance of 40 m in
(a) Vertical direction, and
(b) Horizontal direction
Solution
Given, mass = 20kg
displacement = 40m
(a) In vertical direction work is done against gravity
Work done = mgh = 20 x 9.8 x 40 = 7840J
(b) In horizontal direction
Work done = Fs cos0 = (mg)s cos 0° = 20 x 9.8 x 40 = 7840J
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