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Per NCERT, the CONSERVATION OF MECHANICAL ENERGY principle states which fact?
AFor an object moving under gravity (with no friction / air resistance), the TOTAL mechanical energy stays constant — KE and PE inter-convert but their sum is unchanged
BKE and PE are independent and unrelated
CMechanical energy always increases
DMechanical energy always decreases
Answer & Solution
Correct answer: A. For an object moving under gravity (with no friction / air resistance), the TOTAL mechanical energy stays constant — KE and PE inter-convert but their sum is unchanged
Per NCERT §7.4.3, mechanical energy is conserved when only conservative forces (like gravity) act — KE + PE = constant. The other options misstate.
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