Q130 / 150 · MHT CET 2022 (07 Aug Shift 1) · Physics
A body is executing S.H.M. Its potential energy is ' $\mathrm{P}_1$ ' and ' $\mathrm{P}_2$ ' at displacements ' $x$ ' and ' $y$ ' respectively. The potential energy at displacement $(\mathrm{x}+\mathrm{y})$ is
- A$\sqrt{\mathrm{P}_1}-\sqrt{\mathrm{P}_2}=\sqrt{\mathrm{p}}$
- B$\mathrm{p}_1+\mathrm{p}_2=\mathrm{p}$
- C$\mathrm{p}_1-\mathrm{p}_2=\mathrm{p}$
- Correct answerD$\sqrt{\mathrm{p}_1}+\sqrt{\mathrm{p}_2}=\sqrt{\mathrm{p}}$
Solution
At displacement $\mathrm{x}$
At displacement y
$\mathrm{E}_1=\frac{1}{2} \mathrm{~m} \omega^2 \mathrm{x}^2$
From equations
(1), Or (2) and (3) it follows that
$\sqrt{\mathrm{E}}=\sqrt{\mathrm{E}_1}+\sqrt{\mathrm{E}_2}$
Or $\mathrm{E}=\mathrm{E}_1+\mathrm{E}_2+2 \sqrt{\mathrm{E}_1 \mathrm{E}_2}$
At displacement y
$\mathrm{E}_1=\frac{1}{2} \mathrm{~m} \omega^2 \mathrm{x}^2$
From equations
(1), Or (2) and (3) it follows that
$\sqrt{\mathrm{E}}=\sqrt{\mathrm{E}_1}+\sqrt{\mathrm{E}_2}$
Or $\mathrm{E}=\mathrm{E}_1+\mathrm{E}_2+2 \sqrt{\mathrm{E}_1 \mathrm{E}_2}$Hence, the correct answer is option: 'D'.