A cockroach is moving with velocity `v` in anticlockwise direction on the rim of a disc of radius `R` of mass `m`. The moment of inertia of the disc about the axis is `I` and it is rotating in clockwise direction with an angular velocity `omega`. If the cockroach stops, the angular velocity of the disc will be

Explanation

The phenomenon occurs in the absense of external torque, so applying law of COAM, we have
`I_("disc")omega - mvR = (I_("disc")+mR^(2))omega' rArr omega' = (I omega-mvR)/(I+mR^(2))`