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Per NCERT, when a ball is in FREE FALL from height h, at what point during the fall is its mechanical energy mgh — assuming no air resistance?
AOnly at the top
BAt every point during the fall — mechanical energy stays equal to mgh because PE lost = KE gained
COnly at the midpoint
DOnly at the bottom
Answer & Solution
Correct answer: B. At every point during the fall — mechanical energy stays equal to mgh because PE lost = KE gained
Per NCERT §7.4.3 + Eq. 7.10c, mechanical energy = mgh throughout the fall (PE + KE = mgh always, by conservation).
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