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Question
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, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
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Solution
- The work done is zero because the force acts perpendicular to the displacement.
Work done at angle θ = F × s × cosθ
W = F × s × cos90∘ - The work done is positive because the object's displacement occurs in the direction of the applied force.
- The work done is negative because the object's displacement occurs in the opposite direction of the applied force.
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