Question

If rotational kinetic energy is $50\%$ of total kinetic energy then the body will be:-

• A. Ring
• B. Cylinder
• C. Hollow sphere
• D. Solid sphere

Answer 1

Answer: (A)

Given, $\frac{K_{\text{Rotation }}}{K_{\text{Total }}}100=50\%$
$\Rightarrow \frac{\frac{K^2}{R^2}}{1+\frac{K^2}{R^2}}\times 100=50$
$\Rightarrow \frac{\frac{K^2}{R^2}}{1+\frac{K^2}{R^2}}=\frac{1}{2}$
so, $\frac{K^2}{R^2}=1,$ so it is a ring