Question

state and prove the principal of conservation of angular momentum​

Answer 1

Principle (or law) of conservation of a body is conserved if the resultant external torque on the body is zero. Its angular momentum may change with time due to a torque on the particle. ... ∴ = constant, i.e is conserved. This proves the principle (or law) of convervation of angualar momentum.

Answer 2

Answer:

The linear momentum and angular momentum of the body is given by →p=m→v and →l=→r×→p about an axis through the origin. The angular momentum →l may change with time due to a torque on the particle. ∴→l = constant, i.e. →l is conserved. ... its angular velocity will also change if there is no external torque