People are getting in touch with alot of physics type simulations or games these days, but I have found one really impressive sandbox simulating ALOT in real time.
There are, of course, simple shapes like boxes or circles, but you may want to draw a freehand polygon.
You want to set weight, friction or even air resistance? Do so!
You want to add chains or springs? No problem!
You want to go advance and build a car which is controllable by arrow keys? It is as easy as some mouse clicks.
Water? Even fluid is included (slowing everything down alot if used in masses though)
Enough words, take a look at this [[Rube Goldberg]] device I have built last night:
Now the most interesting part, the link to the
software (and yes, to top all these facts, it is free!):
Phun - 2D physics sandbox
Oh, and if you are wondering "What else can be done?". If you have enough time, you may re-build existing machines, like a clock for example:
