A rod of mass 0.300 kg and length 0.36 m has four small balls mounted on it. Two balls (shown in red on the diagram), each of mass 0.84 kg, are mounted at opposite ends of the rod. Two other balls, each of mass 0.24 kg (shown in blue on the diagram), are each mounted a distance 0.09 m from the center of the rod. The rod rotates on an axle during the center of the rod (indicated by the "x" in the diagram), perpendicular to the rod, and it takes 1.0 seconds to make one full rotation.
stick_4balls
1) What is the kinetic energy of this object?
2) What is the angular speed of the rotating device?
3) What is the moment of inertia of the device about its center?