Saw this and thought it would have great potential for those with the skills to exploit the software fully. The interface looks very user friendly - tool bar sets etc.
Algodoo
"Algodoo gives you the opportunity to play with physics. Use your own hands and simple drawing tools to design, construct and explore the world of physics."
The video link shows how you can create shapes, change the material properties (lots of predefined etc) and setup light sources etc. You could get a very good model of any scope given the time and learning curve.
YT demo below: start at around the 2minute mark, you should get a good idea very quickly of how useful it might be.
https://www.youtube.com/watch?v=mRc40x5wkjk