1. The problem statement, all variables and given/known data What is the moment of inertia of the 4 kg disk below when it rotates about the center of mass? The mass of the disk without the holes is 6 kg . 2. Relevant equations Center of mass equation: (1/M)(∫xdm) Moment of inertia of a disk: I = 0.5mr2 Parallel axis theorem: I = Io + md2 3. The attempt at a solution I tried to find the moment of inertia of the disk without the holes using m = 6 kg and r = 0.12 m. I = 0.5(6 kg)(0.12 m)2 = 0.0432 kgm2 I think I'm supposed to subtract each hole's moment of inertia from 0.0432, but am unsure how to find each circle's radius. Is it simply r = 0.05m? Or is it 0.06m? Or is my line of thinking totally off?