STANDARDPhysics-Rotational Motion
STANDARD Physics Conservation of Angular Momentum MCQ Question
Type: MCQ-conceptual-Medium
A merry-go-round, made of a ring-like platform of radius R and mass M, is revolving with angular speed ω. A person of mass M is standing on it. At one instant, the person jumps off the round, radially away from the centre of the round. The speed of the round afterwards is
A
2ω
B
ω
C
ω/2
D
zero
Correct Answer
Option A
Detailed Explanation
When the person jumps off radially, there is no external torque acting on the system. Hence, angular momentum is conserved. Initially, the angular momentum is Iω, where I is the moment of inertia of the system. After the person jumps, the moment of inertia of the merry-go-round remains the same, but the angular speed doubles to conserve angular momentum, resulting in a final speed of 2ω.
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