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Question
A body is being raised to a height h from the surface of earth. What is the sign of work done by gravitational force?
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Solution
The gravitational force acts in a downward direction and displacement in an upward direction. therefore, the angle between them is θ = 180°.
∴ Work done by the gravitational force
W = Fs cos 180° = – Fs ......(∵ cos 180° = 1)
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