If a gymnast sitting on a rotating stool, with his arms out stretched, suddenly lowers his hands, what will happen?

If a gymnast sitting on a rotating stool, with his arms out stretched,

1.	If a gymnast sitting on a rotating stool, with his arms out stretched, suddenly lowers his hands, what will happen?
Answer» the angular VELOCITY decreases his moment of INERTIA decreases the angular velocity stays constant the angular momentum increases Solution :When hands are lowered R decrease. Moment of inertia I will be DECREASED. Sicne `I=MR^(2)`