A 55.0 kg figure skater holds her arms out horizontally, so each
hand is 0.75 m from her axis of rotation. She rotates with an
angular speed of
0.85 rad/s. The moment of inertia of the skater (not including
hands) is 2.5 kg m2 and is assumed to be constant. She then pulls
her arms inward horizontally to a position 0.100 m from the
rotation axis (a) Find the new angular speed of the skater. (b)
Find the kinetic energy of the rotating system before and after she
pulls her arms inward.
(Assume 2% of her mass is in her hands.)