This problem is making me want to tear my hair off. I am trying to calculate the time it takes for a beam to fall to the ground. http://myweb.lmu.edu/gvarieschi/chimney/Graph1.JPG It would be great if I could calculate the rate of change of angular acceleration, as the acceleration would depend on the angle. The equation for momentum or torque = moment of inertia * angular acceleration = cos(angle) * arm * m*g Here the arm would be equal to the distance from the point of rotation to the center of the mass of the beam. The other equation I find useful is: s = -1/2gt^2 + Vt + s Again, with changing acceleration, I am lost.