Here's a question on a homework assignment that no one understands... A unifrom wheel of mass 10.0 kg and radius .400m is mounted rigidly on the axle through its center. The radius of the axle is 0.200m., and teh rotational inertia of teh wheel-axle combination about its central axis is 0.600 kg.m^2. The wheel is initially at rest at the top of a surface that is inclined at angle (theta=30.0degrees) with the horizontal; the axle rests on the surface while the wheel extends into a groove in the surface without touching the surface. Once released, the axle rolls down the surface smoothly and without slipping. When the wheel-axle combination has moved down the surface by 2.00m, what are (a) its rotational kinetic energy and (b) its translational kinetic energy? The answers are: A-58.8J B-39.2J Obviously its how we got those answers that matters. I don't really know where to start so any help would be appreciated.