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प्रश्न
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
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उत्तर
The displacement of the man and suitcase is along the horizontal direction. Thus, the angle between the displacement and the force of gravity is 90°;
Thus, W = Fd cos 90° = 0
Hence, no work is done against gravity in this case.
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