A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed
of 20 cm/s. How much work is needed to stop it?

The torque experienced by a magnetic dipole, having dipole moment M, when placed in a uniform magnetic field of intensity B is:

A solid sphere & a hollow sphere of radius R are rolling down an inclined plane of height h. The ratio of velocities of Solid sphere to Hollow sphere on reaching the bottom is