A disk-shaped flywheel mass m = 80 kg, and the radius R = 30 centimeters is at rest. And what kind of work you need to do to inform the flywheel frequency n = 10 r / s? What kind of work would have to make if the same mass would drive half the thickness, but twice the radius?

A detailed solution with a brief note of the condition, formulas and laws used in the solution, the derivation of the calculation formula and the answer.