(Solved): 9.42 . You need to design an industrial turntable that is 60.0 cm in diameter and has a kinetic ener ...

9.42 . You need to design an industrial turntable that is 60.0 cm in diameter and has a kinetic energy of 0.250 J when turning at \( 45.0 \mathrm{rpm}(\mathrm{rev} / \mathrm{min}) \). (a) What must be the moment of inertia of the turntable about the rotation axis? (b) If your workshop makes this turntable in the shape of a uniform solid disk, what must be its mass?