WHAT IS MEANING OF MOMENT OF INERTIA?

Moment of inertia is a concept applied for rotational motion. What mass is for linear motion, MI is for rotational motion. The corresponding quantity for force is torque. So the angular acceleration of a body is proportional to the torque applied and inversely proportional to moment of inertia about an axis. MI changes with axis orientation. MI determines how much torque would be required to produced a given angular acceleration about an axis. read less

Moment of inertia is the mass property of a rigid body that determines the torque needed for a desired angular acceleration about an axis of rotation. Moment of inertia depends on the shape of the body and may be different around different axes of rotation. When a body is rotating around an axis, a torque must be applied to change its angular momentum. The amount of torque needed for any given change in angular momentum is proportional to the moment of inertia of the body. Moment of inertia I is defined as the ratio of the angular momentum L of a system to its angular velocity ? around a principal axis, that is Moment of inertia may be expressed in terms of kilogram-square metres (kg•m2) in SI units and pound-square feet (lbm•ft2) in imperial or US units. read less