A man stands holding a weight in each hand and with his arms outstretched on a frictionless platform which is rotating at a speed of 1 revolution per sec. In ths position the total rotational intertia of the man, the weights and the platform is `6kgm^(2)`. If by drawing in his arms, the man decreases the rotational inertia of the system by `2kg m^(2)`, calcualte the resulting speed of the platform and the increase in kinetic energy. How do you account for the increase of kinetic energy?

A gymnast standing on a rotating stool with his arms outstretched, suddenly lowers his arms

If a gymnast sitting on a rotating disc with his arms out stretched suddenly lower his arms, then

A man stands on a rotating platform with his arms stretched holding a 5 kg weight in each hand. The angular speed of the platform is 1.2 rev s^-1 . The moment of inertia of the man together with the platform may be taken to be constant and equal to 6 kg m^2 . If the man brings his arms close to his chest with the distance n each weight from the axis changing from 100 cm to 20 cm . The new angular speed of the platform is.

A man is sitting on a rotating stool with his arms outstretched. If suddenly he folds his arms the angular velocity of the man would

(i) A child stands at the centre of turntable with his two arms out stretched. The turntable is set rotating with an angular speed of 40 rpm. How much is the angular speed of the child if he folds his hands back and thereby reduces his moment of inertia to (2)/(3) times the initial value ? Assume that the turntable rotates without friction (ii) Show that the child's new kinetic energy of rotation is more than the initial kinetic energy of rotation. How do you account for this increase in kinetic energy ?

If a person sitting on a rotating stool with his hands outstretched, suddenly lowers his hands, then his

A person sitting firmly over a rotating stool has his arms stretched. If he folds his arms, his angular momentum about the axis of rotation