Question

what is physical significance of moment of inertia?

Answer 1

If an object is moving, inertia is resistance offered by the subject matter on its motion

The moment of Inertia (MI) is the product of the mass of the object and square of the distance of it from the axis.

Or, I = MR2

Or in other words, the physical significance of the moment of inertia is the resistance offered by the body to its rotational motion. This resistance tends to slow down the speed of the object and ultimately it will stop until an external force is applied to it.

Answer 2

Physical significance of moment of inertia:-)

The mass of a body resist a change in its state of linear motion, it is measure in its inertia and linear motion. Similarly, the moment of inertia of a body about an axis of rotation resist a change in its rotational motion. Thus moment of inertia of of a body can be regarded as the measure of rotational inertia of the body. The moment of inertia of a body plays the same role in the rotational motion as the mass plays in linear motion. That is why moment of inertia is called rotational analogue of mass in linear motion.