1. The problem statement, all variables and given/known data For a physics lab we need to calculate the final linear velocity of a disc and hoop. The only thing we are given is the length and height of the ramp and the mass and radius of the disc and hoop. 2. Relevant equations I thought before that with conservation of energy, I could just set gPE = KE + KErot. 3. The attempt at a solution It seems like all of the radius's and mass's cancel out. I had mgh = .5mv^2 + .5kmr^2(w^2) where w is omega. I then substituted in (v/r) for w and and cancelled out the m's from all of the terms and ended up with gh = .5v^2 + .5kv^2. This doesn't prove to be at all helpful though because I'm nearly positive that not every disc, regardless of its mass and radius, is going to have the same final velocity. Is there some other way I can solve this problem using the work-energy theorem or something with forces? I was thinking that W = change in KE = Fx but does the KE include both linear and rotational KE? Sorry for all of the information, but thanks to anyone that responds!!