I'm a high school physics teacher. I love it. And part of the fun is seeing how the history of science meshes with why things are done a certain way. Where do unit names come from, who decides it, why is the speed of light 'c'? All these things help my students feel connected to the act of "Doing Science" and not just rote memorization or problems.

So, that comes to my conundrum. I cannot find a well sourced explanation of 'p' for momentum. I see several stories, but no sources. It might have come from the Latin petere (Why? No one ever says...). It might be simple random choice (I mean, i guess?) or it might be something else. And I'm not even sure where to start with something like this. So, I come to you, Historians. Does anyone know why momentum is 'p' and where the heck crazy variables names like that come from?