Moment of Inertia

Moment of inertia is defined as the quantity expressed by the body resisting angular acceleration which is the sum of the product of the mass of every particle with its square of a distance from the axis of rotation. Or in more simple terms, it can be described as a quantity that decides the amount of torque needed for a specific angular acceleration in a rotational axis. Moment of Inertia is also known as the angular mass or rotational inertia. The SI unit of moment of inertia is kg m.
Moment of inertia is usually specified with respect to a chosen axis of rotation. It mainly depends on the distribution of mass around an axis of rotation. MOI varies depending on the axis that is chosen.
==Formula==
In general form, I = m \times r^2 
where,
*m = sum of product of the mass
*r = distance from axis of rotation
In integral form, I = \int{dl} = \int_0^M{r^2dm}.
The role of the moment of inertia is the same as the role of mass in linear motion. It is the measurement of the resistance of a body to a change in its rotational motion. It is constant for a particular rigid frame and a specific axis of rotation.
Moment of intertia, I = \sum m_i r_i^2
Kinetic Energy, K = \frac{1}{2} I \omega^2 
Moment of inertia depends on density of the material, shape and size of the body, axis of rotation (i.e. distribution of mass relative to the axis).
Category:Rotation