1. The problem statement, all variables and given/known data A 75 g 30 cm long rod hangs vertically on a frictionless, horizontal axle passing through its center. A 10g ball of clay traveling horizontally at 2.5 m/s hits and stick to the very bottom tip of the rod. To what maximum angle measured from the vertical, does the rod with attached ball of clay rotate? 2. Relevant equations 3. The attempt at a solution I have a few questions as I am writing down things to start this: Can I calculate the moment of inertia for the rod and the moment of inertia for the ball around the pivot point and add those together? Then I think I'll use conservation of energy where K of the ball initial = the rotational kinetic energy of the clay and rod. Then somehow I have to equate that to potential energy. The trouble I'm having is can I just use mgh with the total mass of the ball of clay and the rod as m, or does the fact that this is an extended object make a difference?