Concept:Work is calculated as the dot product of force and displacement. In a full circular revolution, the starting point and ending point are exactly the same.
Formula:$$ W = \vec{F} \cdot \vec{d} = Fd \cos(\theta) $$
Solution:- Because the body completes exactly one full revolution, its net displacement \( \vec{d} \) is 0.
- Therefore, \( W = F \times 0 = 0 \).
- Alternative logic: The centripetal force holding it in a circle acts exactly perpendicular (\( 90^\circ \)) to the instantaneous velocity. Since \( \cos(90^\circ) = 0 \), the work done by a centripetal force is always zero.
Why other options are incorrect:- Option A, Option C, Option D assume you calculate work using the distance (circumference) instead of the vector displacement, which is a fundamental misunderstanding of physics work.
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