1. The problem statement, all variables and given/known data A pendulum is mounted on a vertical, rotating shaft by means of a hinge. The shaft is free to rotate in its bearings. Use conservation laws to eliminate one degree of freedom and simulate the motion of the other one. Analyse and comment using mechanical terms. https://www.physicsforums.com/attachment.php?attachmentid=18687&d=1241008388 3. The attempt at a solution I started out with the Energy principle: E = constant = Kinetic + Potential U = Potential------I = Moment of inertia K= Kinectic------w = angular velocity m = mass------v = velocity L = Length------ θ = Angle K = ½(*I*w2+*m*v2) U = -½*m*g*L*cos θ And i have no idea what to do next, i think i perhaps should derive the energy expression, but i dont know what to derive on, time,angle? Thank you!