Question

A small object of uniform density rolls up a curved surface with an initial velocity v. It reaches up to a maximum height of $\frac{3v^2}{4g}$ with respect to the initial position. The object is

• A. ring
• B. solid sphere
• C. hollow sphere
• D. disc

Answer 1

Answer: (D)

disc

Answer 2

$\frac{1}{2}mv^2+\frac{1}{2}I\bigg(\frac{v}{R}\bigg)^2=mg\bigg(\frac{3v^2}{4g}\bigg)$
$\therefore I=\frac{1}{2}mR^2$
$\therefore$ Body is disc. The correct option is (d).