Q 11-13-100JEE MainJEE Main 2021 (27 Jul, Shift 1)Easy
A particle starts executing simple harmonic motion (SHM) of amplitude $a$ and total energy $E$. At any instant, its kinetic energy is $\dfrac{3E}{4}$, then its displacement $y$ is given by:
Answer: (D) $y = \dfrac a2$
Potential energy $= E - \dfrac{3E}{4} = \dfrac E4$.
$$\frac12 k y^2 = \frac14\cdot\frac12 k a^2 \Rightarrow y = \frac a2$$
Solution by Sreeraj P, M.Sc Physics