Question

A body is rolling without slipping on a horizontal surface and its rotational kinetic energy is equal to its translational kinetic energy. The body is a

• A. disc
• B. sphere
• C. cylinder
• D. ring

Answer 1

The correct option is C cylinder

RE $=\frac{1}{2}I{\omega }^2$

TE $=\frac{1}{2}m{v}^2$

$\frac{1}{2}I{\omega }^2=\frac{1}{2}m{v}^2$

$I{\left(\frac{v}{r}\right)}^2=m{v}^2$

$\frac{I}{r^2}{v}^2=m{v}^2$

$I=m{R}^2$