Angular momentum is a measure of the rotational motion of an object around an axis. It is a vector quantity that takes into account the mass, speed, and distance from the axis of rotation.
Angular momentum can be calculated by multiplying the moment of inertia (a measure of an object's resistance to rotational motion) by the angular velocity (the rate at which an object rotates around the axis).
Angular momentum and torque are directly related. Torque, or the rotational force applied to an object, causes a change in angular momentum. This is known as the law of conservation of angular momentum, which states that angular momentum remains constant unless acted upon by an external torque.
Angular momentum is a measure of rotational motion, while linear momentum is a measure of linear motion. Angular momentum takes into account the rotation of an object around an axis, while linear momentum only considers the movement of an object in a straight line.
A particle moving in a circle has a constant speed but a changing direction, which is why it is considered to have angular momentum. This motion is caused by a centripetal force, which is directed towards the center of the circle and keeps the particle in its circular path.