If the word eccentric is not used correctly, please correct me. 1. The problem statement, all variables and given/known data I am constructing a mathematical model of trebuchet throw. For the throwing part, I simply use the relation [tex] ΔE_p = E_k [/tex], so the change of potential gravitational energy goes into the rotational kinetic energy. I succesfully built the model, but it is oversimplified in at least one point, the arm does not rotate around a point that is "included" in it, but the pivot point is 8 cm above it. What equations can I use to calculate the changes in potential gravitational energy of such body and its moment of inertia? 2. Relevant equations That's my question 3. The attempt at a solution I have a complete model of the situation assuming the pivot point is included in the arm, but have no clue how to make it eccentric.