NEET Physics Question - Oscillation

Assertion (A): For a system executing SHM, the mechanical energy remains constant.

Reason (R): In SHM, kinetic energy and potential energy vary periodically with double the frequency of SHM.

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Solution:

For an ideal SHM, mechanical energy is conserved (A is true). Kinetic energy `\(KE = \frac{1}{2}m\omega^2A^2\cos^2(\omega t)\)` and potential energy `\(PE = \frac{1}{2}k A^2\sin^2(\omega t)\)` vary with `\(2\omega\)`, double the SHM frequency (R is true).
However, R describes the variation of KE/PE, not the reason for conservation of total mechanical energy. Thus, R does not explain A.

Rankers Physics

Mechanical Energy, Kinetic and Potential Energy in SHM

Solution:

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