1. The problem statement, all variables and given/known data Okay, so I'm supposed to take two fresh rolls of toilet paper and drop them. One of which, I am supposed to let unravel while falling. The other, I just drop on its own. I'm supposed to find the height at which both will drop and hit the ground at the same time. 2. Relevant equations Rotation Inertia for Toilet Papers: I= M (R-R2)^2 Conservation of Energy: KE1 + PE1 = KE2 + PE2 3. The attempt at a solution I know that KE1= 0 and PE2 = 0 So PE1 = KE2 mgh = (1/2) Iw^2 + (1/2)Mv^2 Okay... this was all I wrote. At this point I realized, that I did not know the difference between the two. What would make the unraveling toilet paper any different from the one that falls?