Inventor Dynamic Simulation...

So last night I decided to mess around with Dynamic Simulation in Autodesk Inventor, and the video below is what I ended up with.  I watched a video of someone simulating the motion of a trebuchet, so I decided that i was going to build a very basic catapult and see if I could get the simulation to work on it.  So, below is my very basic catapult with the simulated arm motion and ball being thrown.