A body is at rest. Which additional statement is necessary to conclude that it is in equilibrium?
AIt must be at rest only for an instant
BNo other body should be near it
CIt must remain at rest permanently unless disturbed by some external force
DIts speed must be maximum
Answer & Solution
Correct answer: C. It must remain at rest permanently unless disturbed by some external force
The content distinguishes permanent rest from momentary rest. A body is in equilibrium if it remains at rest unless some other force disturbs it; being at rest for just an instant is not sufficient.
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