NEET2009PhysicsRotational MotionActual
A thin circular ring of mass M and radius R is rotating in a horizontal plane about an axis vertical to its plane with a constant angular velocity . If two objects each of mass m be attached gently to the opposite ends of a diameter of the ring, the ring will then rotate with an angular velocity
Options
- A(M-2 m) M+2 m
- BM M+2 m
- C(M+2 m) M
- DM M+m
Correct answer
B. M M+2 m
Step-by-step solution
Key Idea Apply law of conservation of angular momentum. I ₁ ₁= I ₂ ₂ In the given case aligned I ₁ & = MR ^2 I ₂ & = MR ^2+2 mR ^2 ₁ & = aligned Then ₂= I₁ I₂ = M M+2 m