As a student trying to complete his masters in physics I found that the physics portion of Metacreations Carrara was pretty cool. While there were a few bugs (for example some collision detection didn't detect), I think you could make some excellent demos. I haven't tried all of the features of the plug-in, and haven't tried it since Carrara was patched by Eovia. With the plug-in, I have tried a pool-table-type scenario, a ball falling down stairs and more. Animation renders seem to take a little longer using the physics plug-in as compared to key frame animations, but that is likely due to the calculations needed in between each frame of animation. Personally I think you are on the right track. A simple discussion of physics principles is often not enough to maintain interest in the subject. As an undergrad, I worked with one of my profs on setting up relevant demonstrations (not computer generated though) for her first year class so they could visualize what was happening. It is a shame that Eovia wasn't able to offer this tool to their new customers.