A thin circular ring of mass M and radius r is rotating about its axis with constant angular velocity . Two objects each of mass m are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with angular velocity given by
Moments of inertia (MOI) of the ring before attaching the masses I= MR2,
MOI of the ring after attaching the masses I′=(M+2m)R2
Let angular momentum after the attaching the masses ω′
Since there is no external torque, so we use conservation of angular momentum.
I×ω=I′×ω′
⇒MR2×ω=?
⇒ω′=?