Three objects, A : (a solid sphere), B : (a thin circular disk) and C : (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed $$\omega $$ about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation

The moment of the force, $$\overrightarrow F = 4\widehat i + 5\widehat j - 6\widehat k$$ at
(2, 0, –3), about the point (2, –2, –2), is given by

Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities $${\omega _1}$$ and $${\omega _2}$$. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is

A rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angular acceleration of the cylinder if the rope is pulled with a force of 30 N?