Consider a Disc of mass 5 kg, radius 2 m, rotating with angular velocity of 10 rad / s about an axis perpendicular to the plane of rotation. An…

Consider a Disc of mass $\displaystyle 5$ kg , radius $\displaystyle 2$ m , rotating with angular velocity of $\displaystyle 10 \mathrm{rad} / \mathrm{s}$ about an axis perpendicular to the plane of rotation. An identical disc is kept gently over the rotating disc along the same axis. The energy dissipated so that both the discs continue to rotate together without slipping is $\displaystyle \_\_\_\_$J.