Editing Inertia (section)

==Rotational inertia==
A quantity related to inertia is ''rotational inertia'' (→ [[moment of inertia]]), the property that a rotating rigid body maintains its state of uniform [[rotation]]al motion. Its [[angular momentum]] remains unchanged unless an external [[torque]] is applied; this is called conservation of angular momentum. Rotational inertia is often considered in relation to a rigid body. For example, a [[gyroscope]] uses the property that it resists any change in the axis of rotation.