The experimenter fom the video rotates on his stool, this time holding his empty hands in his lap. You stand on a desk above him and drop a long, heavy been bag straight down so that it lands across his lap, in his hands. what happens?

Explanation:

The experimenter is rotating on his stool with angular velocity ω ( suppose )

His moment of inertia is I say

We are applying no torque from outside . therefore , the angular momentum will remain the same

Thus angular momentum L = I ω = constant

Thus we can say I₁ ω₁ = I₂ω₂ = constant

here I₁ is the initial moment of inertia and ω₁ is the initial angular velocity

Similarly I₂ is the final moment of inertia and ω₂ is the final angular velocity

When a been bag is dropped on his lap , his moment of inertia increases due to increase in mass

In the above equation, when moment of inertia increases , the angular velocity decreases . So its motion of rotation will decrease .