Question

A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same, which one of the following will not be affected?

• A. moment of inertia
• B. angular momentum
• C. angular velocity
• D. rotational kinetic energy

Answer 1

Answer: (B)

angular momentum

The solid sphere is rotating in free space. There is no external torque, so angular momentum will be conserved. Momentum of Inertia will change as $I=2m{r}^2/5$, as $r$ changes.

Angular velocity will change as $I\omega =constant$

Also rotational kinetic energy $I{\omega }^2/2$ will change.