HELP! Simulator.....

I think I am going to die trying to find
OpenGL simulator of phisics. Very simple ->
I want to put some objects ,set some properties and then simulate their interaction in real-time. For fun, not for some wicked research. Program does not have to be 3D. I like 2D simulations like BridgeBuilder on download.com.
If you know some, mail me please…
Thanks in advance…
Marko