The moment of inertia (symbol I, SI unit kg·m2) of a rotating object is a measure of what angular acceleration will be produced by a given torque, and can therefore be thought of as the rotational equivalent of mass. It is defined as For a point mass, it is equal to the distance from the centre of rotation squared times the mass of the object, or The moment of inertia is also equal to angular momentum divided by angular velocity, or File:Rotating tube.png This mechanics-related article contains minimal information concerning its topic. You can help the Physics Wiki by adding to it.