1. The problem statement, all variables and given/known data Ok, I have attempted this problem, and believe I have the right answer. My work is not matching up though and I think I am missing something. Question: A hoop is rolling without slipping along a horizontal surface with a speed of 4.50 m/s when it starts up a ramp that makes and angle of 25.0° with the horizontal. What is the speed of the hoop after it has rolled 3.00m up the ramp? 2. Relevant equations KE = 1/2*mv^2 + 1/2*I*w^2 I = mR^2 3. The attempt at a solution This is what I got. Total KE = 1/2*mv^2+1/2*Iw^2 substituting the I = mR^2 and w = v/R Total KE = 1/2*m*v^2 + 1/2*(mR^2)*(v^2/R^2) = 1/2*m*v^2 + 1/2*m*v^2 = mv^2 at 3m up on the incline ke(bot) = pe(top)+ke(top) m*v(initial)^2 = mgh + 1/2*m*v(final)^2 vi^2 = gh + 1/2*vf^2 vf = sqrt(2(vi^2-gh)) I believe at this point I am wanting vf = sqrt(vi^2-gh).. because the answer I believe is 2.80 m/s. sqrt(4.5^2 - (9.8*3sin25)) = 2.80 m/s Am I looking at this correctly? Any help would be appreciated.