1. Tardigrade
  2. Question
  3. Physics
  4. A disc is rotating with angular speed ω. If a child sits on it, what is conserved :-

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. A disc is rotating with angular speed $\omega$. If a child sits on it, what is conserved :-

AIPMTAIPMT 2002System of Particles and Rotational Motion

Solution:

When a child sits on a rotating disc, no external torque is introduced.
Hence the angular momentum of the system is conserved.
But the moment of inertia of the system will increase and as a result, the angular speed of the disc will decrease to maintain constant angular momentum.
[$\because $angular momentum = moment of inertia $\times$ angular velocity]