Hello, I would really appreciate help on this extra credit question... I am struggling with this chapter and need the points. Thank you for your time!

2) A cam is an approximately circular disk attached off center along a shaft. As the shaft rotates about its axis, the disk can be used to push something once every rotation. In internal-combustion engines, for example, this mechanism opens and closes intake and exhaust valves for the combustion chamber in synchronization with the piston's oscillations. One such shaft has radius 2cm and mass 3kg with an attached disk of radius 4cm and mass 0.3kg. The whole unit ("camshaft") is rotating at 300rpm. 8 cm Axis of rotation 4 cm Front view What is its rotational kinetic energy? (5 points)