Question

The angular momentum of a system of particles is not conserved. When?

Answer 1

Let us first discuss angular momentum before moving on to the question. The angular momentum of a rigid object is the product of its moment of inertia and its angular velocity. If there is no external torque on the object, it has linear momentum and is subject to the conservation of angular momentum principle's fundamental constraints. A vector quantity is referred to as "angular momentum." It can be calculated using the expression for angular momentum of a particle.

Complete step-by-step solution:
The torque is equal to the cross product of the linear force and the distance from the axis. As a result, the torque is the rate at which angular momentum changes.
When there is a torque, angular momentum is not conserved. Newton's third law can be used to demonstrate that there are no net internal torques in a closed system. As a result, changing angular momentum necessitates the application of external torque. When there is a torque, angular momentum is not conserved. $J = I\omega$ = Constant when external torque is applied, angular momentum is not conserved.

Note: Angular momentum is a big number; the overall angular momentum of a composite system is equal to the sum of its constituent members' angular momenta. For a continuous rigid body or a fluid, total angular momentum is the volume integral of angular momentum density (i.e. angular momentum per unit volume in the limit as volume decreases to zero) throughout the entire body.