Awhile back we had soy.bodies, soy.shapes, and soy.models all as separate modules containing nearly identical classes which, in almost every case, were applied together and having them separate just made code 3 times as long.

There's one piece that this could also be said for that didn't make it into that process: soy.Mass. Refactor its functionality into the respective soy.bodies classes and change soy.bodies.Body.mass into soy.bodies.Body.weight, a float value.

Update at least one PySoy example to demonstrate this working such as two bodies of different masses (eg, 2:1 ratio) bouncing around a Room.

While working on this task you should join and remain in #PySoy on Freenode to get help, feedback, and guidance from mentors and other developers. Code updates which may affect your work are also announced here as they happen.

When you've done, commit your work and post the resulting changeset url to this task.