Moment of inertia is a physical property of a rigid body that determines its resistance to changes in rotational motion. It is a measure of how mass is distributed around an axis of rotation.
The moment of inertia of a rigid body can be calculated by multiplying the mass of the body by the square of its distance from the axis of rotation.
Torque about point O of a rod is the measure of the force that causes the rod to rotate about point O. It is calculated by multiplying the force applied to the rod by the perpendicular distance between the point of rotation and the line of action of the force.
Torque about point O of the rod can be related to moment of inertia through the equation τ = Iα, where τ is the torque, I is the moment of inertia, and α is the angular acceleration.
The moment of inertia of a rigid body is affected by its mass, shape, and distribution of mass around the axis of rotation. Objects with more mass and mass distributed farther from the axis of rotation will have a higher moment of inertia.