Moment of inertia is a physical property of a rotating object that describes its resistance to changes in rotational motion.
Moment of inertia is a measure of an object's rotational inertia, while mass is a measure of its inertia in linear motion. In other words, moment of inertia describes how difficult it is to change the rotation of an object, while mass describes how difficult it is to change its position or speed.
The moment of inertia of an object depends on its mass, shape, and distribution of mass around its axis of rotation. Objects with more mass and a greater distance from the axis of rotation have a higher moment of inertia.
The moment of inertia of a point mass is calculated using the equation I = mr^2, where I is the moment of inertia, m is the mass of the object, and r is the distance from the object's axis of rotation to the point mass. For objects with a continuous distribution of mass, the moment of inertia is calculated using an integral.
Moment of inertia is important in understanding and predicting the rotational motion of objects. It is also used in engineering and design to determine the stability and efficiency of rotating systems, such as motors, propellers, and flywheels.