1. The problem statement, all variables and given/known data 1. A ring 1.5 m in diameter is pivoted at one point on its circumference so that it is free to rotate about a horizontal axis. Initially, the line joining the support and center is horizontal. What must be the initial angular velocity be if the ring is to make just a complete revolution ? 2. A wheel starts from rest with a constant angular acceleration of 2.6 rad/s^2 and rolls for 6 s. At the end of that time. (a) Through what angle has the wheel turned ? 2. Relevant equations Ei=Ef [tex]\tau[/tex]=I*[tex]\alpha[/tex] 3. The attempt at a solution 1. I use conservation of energy. Ei=(1/2)*I*[tex]\omega[/tex]i2 Ef= (1/2)*I*[tex]\omega[/tex]i2 I can calculate I= 2*M*R^2. I substitute I into the conservation of energy equation and get R*[tex]\omega[/tex]i2 - R*[tex]\omega[/tex]f2= g. How do I continue to solve for [tex]\omega[/tex]i 2. I integrate the acceleration from 0 to 6 and get the velocity right as 15.6 rad/s. Then to get the angle I integrate velocity from 0 to 6 and get 93.6 rade. However I am wrong. The result should be 46.8 rad. What did I do wrong ? How do I correct it ?