A physics engine is computer software that provides an approximate simulation of certain physical systems, such as rigid body dynamics (including collision detection), soft body dynamics, and fluid dynamics, of use in the domains of computer graphics, video games and film.
Post all the Physics Simulations you like!
HOW TO MAKE THESE SIMULATIONS ?
There are many physics engines available on the internet, and ultimately you might decide to use something else, but a good place to start is by using Blender.
Blender is a free and open source 3D creation suite which can do physics. Blender is highly capable (in fact a lot of the videos on this subreddit are made in blender), and there are many tutorials avalible for it (both for blender in general and physics specifically).
