Angular momentum is a physical quantity that represents the rotational analog of linear momentum. It is a conserved quantity, meaning that the total angular momentum of a closed system remains constant. Angular momentum has both a direction and a magnitude, and both are conserved.

Here are some key points about angular momentum:

• Angular momentum is an extensive quantity, meaning that the total angular momentum of any composite system is the sum of the angular momenta of its constituent parts.

• Angular momentum is a vector quantity that represents the product of a bodys rotational inertia and rotational velocity (in radians/sec) about a particular axis.

• For a continuous rigid body or a fluid, the total angular momentum is the volume integral of angular momentum density (angular momentum per unit volume in the limit as volume shrinks to zero) over the entire body.

• Angular momentum can be considered a rotational analog of linear momentum. Like linear momentum, it involves elements of mass and displacement.

• Angular momentum is important in many physical phenomena, such as the motion of bicycles and motorcycles, flying discs, rifled bullets, and gyroscopes.

• Angular momentum is also important in astronomy, where it plays a role in the motion of planets, stars, and galaxies.

In summary, angular momentum is a fundamental concept in physics that describes the rotational motion of objects. It is a conserved quantity and has both a direction and a magnitude.