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Martial Arts

  1. Jan 20, 2004 #1
    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.
  2. jcsd
  3. Jan 21, 2004 #2
    I don't think that force is the appropriate measure. I think that pressure is more pertaining to the question.
  4. Jan 21, 2004 #3


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    A lot of what you're asking depends on the chain and the sword.

    Chains vary in strength from gold wire which can be broken with fingers to massive chains used to hold boats in place wich have links made out of steel several inches thick. Similarly, the material and shape of the sword is important. Is the sword a laser cutter, or a baguette?

    Once you have determined the materials that you are using, you can start talking about how the chain is going to be broken.

    Of course, there's always a question of geometry as well.

    So, regarding your question:

    Can someone with a bronze dagger use it to break a steel anchor chain? No.

    Can someone with a claymore use it to bust a gold neclace? Almost certainly.

    What you want to know about is probably somewhere between those two. In practice, sawing through chains is easier and safer.
  5. Jan 21, 2004 #4


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    I believe Adam was talking about chain-male armor, not a chain like an anchor chain. In comparing chain-male to a nail, I think the most important fact to remember is that chain-male is made to give way when struck, much like today's bullet-proof vests. So whatever amount of energy is required to bring your sword to a halt, that energy is spread out over a short amount of distance (about 1 or 1 1/2 inches), and a short period of time. This makes chain-nale armor much more resistant to breakage than a nail stuck in wood.
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