A figure skater rotating at 3.4 rad/s with arms extended has a moment of inertia of 2.97 kg ∙ m2. If he pulls in his arms so his moment of inertia decreases to 1.9 kg ∙ m2, what is the final Kenetic energy?

A playground carousel is free to rotate about its center on frictionless bearings, and air resistance is negligible. The carousel itself (without riders) has a moment of inertia of 125-kg*m2. When one person is standing on the carousel at a distance of 1.50 m from the center, the carousel has an angular velocity of 0.600 rad/s. However, as this person moves inward to a point located 0.832 m from the center, the angular velocity increases to 0.800 rad/s. What is the person's mass?

2 25,551 F2 W S X mand 3 2. Two disks are rotating about the same axis. Disk A has a moment of inertia of 4.80 kg.m² and an angular velocity of +7.60 rad/s. Disk B is rotating with an angular velocity of -12.0 rad/s. The two disks are then linked together without the aid of any external torques, so that they rotate as a single unit with an angular velocity of -2.40 rad/s. The axis of rotation for this unit is the same as that for the separate disks. What is the moment of inertia of disk B? kg.m² 20 20 F3 E D C 22 $ 4 888 F4 R F % 5 F5 V T مال G tv ^ 6: B MacBook Air Y A I & 7 N F7 U * 00 8 DII F8 1 M ( 9 K MOSISO DD FO ) O O Р C command F11 + 11 PER 480 21 ? 1 option quies or roe puffer F12 ISOI P by m 04 M delete

A flywheel is a solid disk that rotates about an axis that is perpendicular to the disk at its center. Rotating flywheels provide a means for storing energy in the form of rotational kinetic energy and are being considered as a possible alternative to batteries in electric cars. The gasoline burned in a 189-mile trip in a typical midsize car produces about 1.12 x 10⁹ J of energy. How fast would a 48.7-kg flywheel with a radius of 0.290 m have to rotate to store this much energy? Give your answer in rev/min. Number Units