1. The problem statement, all variables and given/known data A 75kg, 30 cm long rod hangs vertically on a frictionless, horizontal axle that passes through its centre. A 10kg ball of clay travelling horizontally at 2.5 m/s hits and sticks to the very bottom tip of the rod. To what maximum angle (measured from the vertical) does the rod (with the clay ball attached) rotate? 2. Relevant equations 3. The attempt at a solution Not sure where to start on this, apart from calculating the moment of inertia for the rod and for the ball and adding them together to get a total inertia? From there, I have no clue.