1. The problem statement, all variables and given/known data Alright, so say I have a solid wood disk, and a hollowed out disk of equal mass. I roll them both down an incline, which one gets to the bottom first and why? The scenario is very similiar to this: http://youtube.com/watch?v=7mxV6f5nuJY 2. Relevant equations I = MR ? 3. The attempt at a solution Something do with moment of inertia i think. Thanks alot.