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Moment of inertia is a physical property of a rotating object that measures its resistance to changes in its rotation. It is also known as rotational inertia.
Moment of inertia is specific to rotating objects, while mass is a measure of an object's resistance to changes in its linear motion. Moment of inertia takes into account not only an object's mass, but also its distribution of mass around its axis of rotation.
The formula for calculating moment of inertia depends on the shape and distribution of mass of the object. For a point mass rotating around an axis, it is given by I = mr^2, where m is the mass and r is the distance from the axis of rotation. For more complex shapes, such as a solid cylinder, the formula is I = 1/2mr^2.
The moment of inertia determines how an object will respond to external forces causing it to rotate. Objects with higher moment of inertia will require more torque to change their rotational speed or direction, while objects with lower moment of inertia will rotate more easily.
Moment of inertia is important in many areas of physics and engineering, such as designing rotating machinery, understanding the motion of celestial bodies, and analyzing the performance of sports equipment like ice skates and bicycles.
