(Jon of the Clue Crew shows himself on the monitor, swiveling around in a chair with dumbbells in his hands, extending and contracting his arms.)  When I draw my arms inward, my angular velocity increases because my angular mass decreases; the product of those two quantities is called angular this
[DOC] [TLE] Change in Angular Momentum - MIT [PAR] Product rule ... Torque and the Time Derivative of Angular Momentum: Point 
Particle ... A person spins a tennis ball on a string in a horizontal circle with 
velocity (so that the ... she reduces her rotational moment of inertia and her 
angular speed increases.