A smooth cylinder lying on a horizontal surface is in neutral equilibrium

A smooth cylinder lying on a horizontal surface is in neutral equilibrium

A couple produces rotational motion.

The algebraic sum of the forces, constituting the couple is zero.

The algebraic sum of the forces, constituting the couple, about any point is the same.

A couple cannon be balanced by a single force but can be balanced only by a couple of opposite sense.

The point, through which the whole weight of the body acts, irrespective of its position, is known as centre of gravity.

The term 'centroid' is the same as centre of gravity.