This video is a little dated but shows the power of Sketchup and its plugin repository.

The ability to simulate physical environments in real time, within a drawing program is insanely powerful as you can make rapid updates to physical geometry and simply run the simulation again.

SketchyPhysics was developed many years ago by CPhilips and is a brilliant application of the Newton physics engine.

Here is the link so you can download and play with SketchyPhysics yourself.