Moment of Inertia: Dance Moves

I was watching America's Best Dance Crew and I noticed that Quest Crew had some pretty cool dance moves. I saw that one of the dancers applied physics in terms of moment of inertia and angular momentum. Moment of Inertia is determined by the mass and the distribution of the mass and is basically a measurement determining if an object is easily or not easily able to be rotated. So the formula is I= mr^2. So a object that can easily be rotated and likewise easily to be stopped rotating has a small moment of intertia and vice versa. So something can be easily to be rotated resulting in a small moment of intertia if most of its mass is located close to the axis of rotation. In ABDC, the dancer is doing a headspin and he is rotating quickly when his arms are in because he has a small moment of inertia. However, he puts his arms and legs out as he spins and he appears to slow down, this is a result of the change in the distribution of mass, making his moment of inertia to increase. And once again he brings his arms in again and he appears to speed up because he is easier to be rotated. This dancer also demonstrates angular momentum and it conservation. Angular momentum is determined by multiplying the moment of inertia and the angular speed. The momentum is conserved throughout because when he brings his limbs out his moment of inertia increases, but his angular speed decreases and when he brings his limbs in his moment of inertia decreases and his angular speed increases following the law of conservation of momentum. Hope you enjoy the short clip!