A dancer is spinning with his arms extended. In this position his rotational inertia is 1.5 kg m?. During the spin, the dancer pulls the arms close to his body. In this position his rotational inertia is 0.5 kg m?. Ignore friction with the air or with the floor. If the dancer's final angular velocity is 3.6 rev/min, what was his initial angular velocity with the arms extended?

A ballerina spins initially at 1.56 rev/s when her arms are extended. She then draws in her arms to her body and her moment of inertia becomes 0.82 kg-m², and her angular speed increases to 4.43 rev/s. What was her initial moment of inertia? Give your answer in kg-m².

A person sits in a chair that is free to rotate without friction. Intheir hands, they hold two masses: Mass m1 = 5.0 kg a distance r1 = 0.35m  from their body and mass m2 = 3.0 kg a distance r2 = 0.75 m from their body. a. At what distance r1 should the person hold mass m1 if they want to change their rotation speed from w1 = 8.0 rad/s to wf = 5.0 rad/s? b. What is the new moment of inertia about the vertical axis when m1 is held at this new distance?

A wheel rotates clockwise about its central axis with an angular momentum of 600Kg.m 2 /s.At time t= 0, a torque of magnitude 50N.m is applied to the wheel to reverse the rotation. If the same torque is maintained, at what time will the angular momentum be counter-clockwise of 600Kg.m 2 /s?