Problem: A student sitting on a frictionless rotating stool has rotational inertia 0.90kg•m2 about a vertical axis through her center of mass when her arms are tight to her chest. The stool rotates at 7.30 rad/s and has negligible mass. The student extends her arms until her hands, each holding a 3.9 kg mass, are 0.72 m from the rotation axis.
Part I: Ignoring her arm mass, what's her new rotational velocity?
Part II: Repeat if each arm is modeled as a 0.72m long uniform rod of mass of 5.0kg and her total body mass is 64kg.
Rework your solution from the starting and check each step carefully.