Construct Your Own the work done by a spinning skater pulling her arms in to increase her rate of spin. Construct a problem in which you calculate the work done with a “force multiplied by distance” calculation and compare it to the skater’s increase in kinetic energy.
Step-by-step solution Step 1 of 9 A skater of mass 60 kg is spinning in a circle with both arm stretched. In order to increase the angular speed, the skater brings his arm in. The body is considered as a cylinder of radius 0.25 m. Mass of each arm is 2.5 kg. Length of each arm is 0.75 meter. Find the change in rotational kinetic energy of the skater if she brings her arm in. the initial angular speed of the skater is . Step 2 of 9 The moment of inertia of the skater when her arm are stretched is, Here is the mass of skater, is radius, is initial moment of inertia, is the mass of each arm is the radius of each arm. Step 3 of 9 Substitute for , for , for and for . Step 4 of 9 The moment of inertia of the skater when she brings her arm in, Here is the mass of skater, is radius and is final moment of inertia. Step 5 of 9 Substitute for , for .