The video's linked below are a series of examples of using Rigid Bodies in Autodesk Maya and how they affect the weight of objects and collide with one another when in motion.
The above ball and chain animation went quite well I think. Although I do wonder if I should have made the weight a little 'heavier' (more mass or something) to really hammer home the jarring weight of the ball on the chain.
The catapult is definitely in need of some further tweaking, I settled with this version mainly because this was the only time the entire wall fell apart, despite the fact it wasn't exactly a direct hit. The only other nitpick I have is that I should have incorporated the walls as rigid bodies as some of the bricks and canon-ball glitch through towards the end and fall off the floor plane.
I can see the potential for this particular animation technique. Equal and opposite reactions will really add a sense of realism to a short animation.
Above is a rigid bodies test using Newtons Cradle. I had to dial back the power slightly when forcing the first weight up ready for the fall, for some reason it shot over almost 180 degrees. The end result is satisfactory although I'm not sure if the motion was slowly decaying or not. In any case the principle is there.
Finally active and passive rigid bodies helped to create authentic swinging motion in the earring, but also collisions against the face. Without it the earring would slip straight through the side of the jaw. I had a few issues with this one. fortunately working out my mistake I reapplied gravity and when I really couldn't understand what was happening a restart of Maya seemed to solve it!