A skinny student (40 kg) sits on a stool that can rotate, holding two 8 kg bowling balls with his arms out stretched. The stool weighs 20 kg. The student and stool are spun such that they have an angular velocity of 2 rad.s-1. When the student pulls his arms in towards him, what happens to his angular velocity and what is his final angular velocity when they rest in his lap? I know I have to find [tex]\omega[\tex] and I think using [tex]L=I\omega[\tex] should be the key. Only L and I are unknown..any ideas?