1. The problem statement, all variables and given/known data I am still - STILL - looking for the rotation-translation equation. You guys have a clue? If a pool ball (radius 57mm, mass 160g) has a forward rotation of 300mm / s and backspin of 6 pi rad / s (which is 1074mm / s at the point of contact)... after one second, what are the ball's coordinates and what are its velocities? After two / three / four seconds? When will it stop? (Make up coefficients you don't know, including the rolling / static / dynamic friction coefficients.) 2. Relevant equations Most can be found here - http://archive.ncsa.illinois.edu/Classes/MATH198/townsend/math.html" [Broken] . I did find these equations, but I'm not sure if they're right - if they are, can you just tell me they're correct? I'm too tired right now to figure out if these are what I'm looking for. 3. The attempt at a solution I apologize, all of the attempts I made came purely from my head and were not grounded on physical laws. They looked like... something was happening, but I have no way to tell if I was close.