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Which statement best defines work done by a force in mechanics?
AWork is the product of force and time
BWork is the dot product of force and displacement
CWork is the rate of change of momentum
DWork is the product of mass and acceleration
Answer & Solution
Correct answer: B. Work is the dot product of force and displacement
Work is defined as the dot product $\vec F \cdot \vec s$, so it depends on both the magnitudes of force and displacement and the angle between them. This is why work can be positive, negative, or zero.
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