# angular momentum

## angular momentum

*noun*

## Definition of *ANGULAR MOMENTUM*

**:**a vector quantity that is a measure of the rotational momentum of a rotating body or system, that is equal in classical physics to the product of the angular velocity of the body or system and its moment of inertia with respect to the rotation axis, and that is directed along the rotation axis

## First Known Use of *ANGULAR MOMENTUM*

## angular momentum

*noun*

*(Concise Encyclopedia)*

Property that describes the rotary inertia of a system in motion about an axis. It is a vector quantity, having both magnitude and direction. The magnitude of the angular momentum of an object is the product of its linear momentum (mass *m* velocity *v*) and the perpendicular distance *r* from the centre of rotation, or *m**v**r*. The direction is that of the axis of rotation. The angular momentum of an isolated system is constant. This means that a rigid spinning object continues to spin at a constant rate unless acted upon by an external torque. A spinning gyroscope in an airplane remains fixed in its orientation, independent of the airplane's motion, because of the conservation of direction as well as magnitude.

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