Question

If a gymnast sitting on a stool with his arms stretched lower his arms then what happened with angular speed

Answer 1

We know , L = I. ω …………………………..(1)
Where, L = angular momentum ; I = moment of Inertia ; ω = angular speed
Now when the gymnast sitting on a stool with his arms stretched lower the moment of inertia will decrease. Again we know total angular momentum is constant.
So, as per equation (1), L is constant, I (moment of inertia) will decrease then ω must be increased.

Answer: Angular speed will increased.