$A$ rigid body of mass $2 \ kg$ is moving in a circular path of radius $0.8 \ m$ with an angular velocity of $44 \ rad \ s^{-1}$. If the radius of the circular path becomes $1 \ m$,the new angular velocity of the body will be ........ $rad \ s^{-1}$.

If the value of torque is zero,then

$A$ boy runs and sits on a rotating platform. Which of the following quantities will be conserved?

$A$ thin uniform circular disc of mass $M$ and radius $R$ is rotating with angular velocity $\omega$ in a horizontal plane about an axis passing through its centre and perpendicular to its plane. Another disc of the same radius but of mass $\frac{M}{2}$ is placed gently on the first disc co-axially. The new angular velocity will be

If the torque applied on a particle is zero,then its angular momentum will be:

$A$ smooth tube of certain mass closed at both ends is rotated in a gravity-free space and released. The two balls shown in the figure move towards the ends of the tube and stay there. Which statement is incorrect about this whole system?