The outstretched hands and arms of a figure skater preparing

Last updated: 6/24/2023

The outstretched hands and arms of a figure skater preparing for a spin can be considered a slender rod pivoting about an axis through its center Ibar 12m 1 where is the length of the bar When the skater s hands and arms are brought in and wrapped around their body to execute the spin the hands and arms can be considered a thin walled hollow cylinder The hands and arms have a combined mass 7 kg When outstretched they span 1 5 m When wrapped they form a cylinder of radius 30 cm The moment of inertia about the rotation axis of the remainder of the body is constant and equal to 0 4 kg m If the original angular speed is 0 6 rev s what is the final angular speed W 1 00 rev s Determine how much the figure skater s rotational KE increased NOTE We express energy in J To get J you must convert your angular velocities to the appropriate mks units which are rad s AKE