The masses of a solid cylinder and hollow cylinder ate 3.2 kg and 1.6 kg respectively. Both the solid and hollow cylinders start from rest from the top of an inclined plane and roll down without slipping. If both the cylinder have equal radius and the acceleration of solid cylinder is $4 \mathrm{~ms}^{-1}$, the acceleration of hollow cylinder is

A solid sphere of mass 50 kg and radius 20 cm is rotating about its diameter with an angular velocity d 420 rpm . The angular momentum of the sphere is

A block $P$ is rotating in contact with the vertical wall of a rotor as shown in figures $A, B, C$. The relation between angular velocities $\omega_A, \omega_B$ and $\omega_C$, so that block does not slide down. ( $R_A < R_b < R_c $ radii)

The moment of inertia of a solid sphere of mass 20 kg and diameter 20 cm about the tangent to the sphere is