This project is a simple simulation/visualization of some physics concepts like gravity, collisions or acceleration in 2D.
Live demo is available at https://martinheinz.github.io/physics-visual/
You can create new objects by clicking and holding left mouse button - the longer you hold the bigger the objects will be.
There are preconfigured example which you can use by clicking on buttons in top right.
You can find more information about this project/repository and how to use it in this blog post: