In addition to the question in https://www.physicsforums.com/showthread.php?s=&threadid=12538 I have a few other queries related to combat. I've read that the it requires about 900-950 Newtons to shear an average iron nail. I'm wondering how much would be required to slash through chain or steel mail armour with a sword, given that the links are made of rings generally about the thickness of a nail. It's generally no problem for the human body to exert over a thousand Newtons when lifting at the gym, for example, but I'm not sure how much force is involved if we swing a sword and it is focused into that small area (the point of impact from a sword). Ah, in general, I guess what I'm asking is, how do I work out the forces involved in the swing of a weapon of fist or such? How much body mass do I include, how much movement of the entire body is added to the speed of a swing, et cetera. PS: The Momentum thread was kinda funny.