A ring of mass M and radius R is rotating with angular speed a about a...
To solve this problem, let's consider the conservation of angular momentum.
1. Conservation of Angular Momentum:
The angular momentum of a rotating object is given by the equation L = Iω, where L is the angular momentum, I is the moment of inertia, and ω is the angular velocity. In this case, the ring and the two masses contribute to the total angular momentum of the system.
2. Initial Angular Momentum:
At the initial instant, the angular velocity is given as ω. The moment of inertia of the ring is MR²/2, and the moment of inertia of each mass at O is zero since they are at rest. Therefore, the total initial angular momentum is L₀ = (MR²/2)ω.
3. Final Angular Momentum:
At the final instant, one of the masses is at a distance of R from O, which means it has moved radially outwards. The other mass is not mentioned, so we need to find its distance from O.
4. Conservation of Angular Momentum Equation:
According to the principle of conservation of angular momentum, the initial angular momentum L₀ is equal to the final angular momentum L₁. Since the moment of inertia of the ring remains the same and the masses move radially, the moment of inertia of the system remains constant.
5. Deriving the Equation:
L₀ = L₁
(MR²/2)ω = (MR²/2)a + m₁r₁²ω₁ + m₂r₂²ω₂
Since the masses are at rest at O, ω₁ and ω₂ are both zero.
(MR²/2)ω = (MR²/2)a + m₁r₁²(0) + m₂r₂²(0)
(MR²/2)ω = (MR²/2)a
ω = a
6. Solving for the Distance:
ω = a implies that the angular velocity at the final instant is equal to the angular acceleration. Substituting this in the equation above:
(MR²/2)a = (MR²/2)a + m₁r₁²(0) + m₂r₂²(0)
(MR²/2)a = (MR²/2)a
This equation is satisfied for any values of r₁ and r₂ as long as m₁ + m₂ = M.
7. Conclusion:
Since the equation is satisfied for any values of r₁ and r₂, the distance of the other mass from O can be any value as long as m₁ + m₂ = M. Therefore, the distance of the other mass from O cannot be determined based on the given information. The correct answer is (None of the above).
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