Question

Derivation of law of conservation of angular momentum

Answer 1

According to the second law of motion net force acting on a body is equal to its rate of change of linear momentum.

i.e.

Taking vector product of on both side if above expression

.

But is the torque acting on the body

... (i)

Angular momentum is defined as:

= x

Differentiating both sides with respect to "t"

Which is the required equation.

This expression states that the torque acting on a particle is the time rate of change of its angular momentum. If the net external torque on the particle is zero, then,

OR

Integrating both sides