Item 19 A student with arms outstretched stands on a platform that is rotating with a constant angular speed. The student then pulls his arms inward. This will result in

An increase in angular speed due to conservation of energy priciple.

Explanation:

This leads to a decrease in your moment of inertia. This means that your angular velocity must increase as a result of conservation of energy principle and therefore you will spin faster.

It's also the same way this conservation of energy principle applies to ice skaters that makes them spin faster when they suddenly draw their arms inwards.