1. The problem statement, all variables and given/known data A thin 1.0-meter-long rod pivoted at one end falls (rotates) from a horizantal position, starting from rest and with no friction. What is the angular speed of the rod when it is vertical? 2. Relevant equations I (of the thin rod) = (1/3)ML^2 3. The attempt at a solution I tried solving this problem using conservation of energy, but I'm not getting the right answer (5.4 rad/s). For kinetic energy, I was using (1/2)I[tex]\omega[/tex]^2; and for potential energy, I was using mgL. Then I solved for [tex]\omega[/tex]. What's wrong with that?