A body is executing simple harmonic motion. At a displacement ' $x$ ' its potential energy is, $E_1$ and at…
A body is executing simple harmonic motion. At a displacement ' $x$ ' its potential energy is, $E_1$ and at a displacement ' $y$ ' its potential energy is $E_2$, The potential energy E at a displacement $(x+y)$ is
$\sqrt{E}=\sqrt{E_1}-\sqrt{E_2}$
$\sqrt{E}=\sqrt{E_1}+\sqrt{E_2}$
$E_1=E_1-E_2$
$E_1=E_1+E_2$
Solution
For a body executing SHM,
$\begin{aligned}
& E_1=\frac{1}{2} k x^2, E_2=\frac{1}{2} k y^2 \\
& \therefore E=\frac{1}{2} k(x+y)^2=\frac{1}{2} k\left(x^2+y^2+2 x y\right) \\
& =\frac{1}{2} k x^2+\frac{1}{2} k y^2+2\left[\frac{1}{2} k(\sqrt{x y})^2\right] \\
& =E_1+E_2+2 \sqrt{E_1 E_2}=\left(\sqrt{E_1}+\sqrt{E_2}\right)^2 \\
& \therefore \sqrt{E}=\sqrt{E_1}+\sqrt{E_2}
\end{aligned}$