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In each of the following a force, F is a...

In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow, observe the diagrams carefully and state Wheather the work done by the force is a negative, positive or zero.

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Case (i) In the direction of force acting on the block is perpendicular to the displacement. Therefore, work done force on the block will be zero.
Case (ii) In this case, the direction of force acting on the block is in the direction of force acting on the block is in the direction of displacement. Therefore, work done by force on the block will be positive.
Case (iii) In this case, the direction of force acting on the block is opposite to the direction of displacement. Therefore, work done by force on the block will be negative.
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