A disc of radius `0.5 m` is rotating about an axis passing through its centre and perpendicular to its plane. A tangential force of `2000 N` is applied to bring the dics to rest `2 s`. Calculate its abgular momentum.

Explanation

Wheel is a rigid body , the particles that consiture the wheel do experience a centripetal acceleration directed towards the centre , this acceleration arises due to internal eleastic forces , which cancel out in pairs.
In a half wheel the distribution of mass about its centre of mass (through which axis of rotation passes ) is not symmetrical , therefore , the direction of angular momentum of the wheel does not coincide with the direction of its angular velocity Hence an external torque is required to maintain the motion of the half wheel.