Question

What is the physical significance of second moment of inertia?

Answer 1

Answer:

So for a given moment or torque on a body, lower will be its angular acceleration. The area moment of inertia is a property of a two-dimensional plane shape which characterizes its deflection under loading

Answer 2

Rotational inertia is important in almost all physics problems that involve mass in rotational motion. It is used to calculate angular momentum and allows us to explain (via conservation of angular momentum) how rotational motion changes when the distribution of mass changes.