Angular momentum, L=Iω The moment of inertia of the circular ring, I=Mr2 When masses are attached at diametrically opposite ends, the moment of inertia, I′=Mr2+2mr2 The new angular speed =ω′ So, the new angular momentum, L′=I′ω′ Using the law of conservation of angular momentum Iω=I′ω′ ⇒Mr2ω=(Mr2+2mr2)ω′ ⇒ω′=