Specific situation : A ring of mass M and radius R is rotating about its axis with angular velocity w. Two identical bodies each of mass m are now gently attached at the two ends of a diameter of the ring. Because of this, the kinetic energy loss will be?
I can find out the KE loss by finding final w by conservation of angular momentum.
But my query is why is angular momentum conserved and KE not conserved? I don't see any work done by an external torque. Will we consider friction between the two bodies of mass m and the ring?