Magic sword vs. Faerie Might

[Ponderingturtle]

@callen

@Ponderingturtle

Concentrating the mass at the end increases the rotational inertia and thus energy available.

Careful, you're starting to veer very, very far from how the factors are important. If that were actually the case, why not use a much longer haft with a slightly lighter head? That would create more rotational inertia. Why not just use five times as much mass on the head? That would concentrate the mass more at the head and increase the rotational inertia. Here's a modern case: why do you use an axe to fell a tree and not a maul? (There's an additional point to the axe vs. maul that I've included at the end because you should split wood with a maul instead of an axe and there is a reason for that.)

Those would all make the tool hit harder, the thing is that you do not always want to hit as hard as possible. As for the maul felling a tree, it has the wrong blade geometry for that, and at that weight it would be a real pain in the ass to use. But it would hit far harder. Putting a longer handle on a hammer would also make it hit harder, but again it is a trade off for control. It would be hard to accurately hit a nail with a claw hammer on a 4' handle. Hence why people choke up on hammers sometimes inspite of the way that reduces head velocity and hitting power.

I might have been over stressing rotational innertia but that is a bit of an over statment but the energy of the object is by far what matters.

@Ponderingturtle

As for claiming the wrist is so strong try to see how much force you generate by pushing on something with just the wrist. Why do you think that you keep your wrist straight when you really push on something instead of depending on the strength of the wrist to handle torque?

Please reread what I wrote about the direction of the applied force. You seem to get it when you talk about keeping your wrist straight. That's exactly the type of situation we're examining. So, let's clarify some things:

Then you are talking more about a thrust than a swing.

1. What we care about is, as I said earlier the force applied in the direction straight down the arm, through the wrist, through the palm of the hand. We're not talking about how well the wrist can rotate or keep itself from rotating. That only becomes an issue if you don't know how to land the strike and are really crooked. This relevant portion of the force is exerted perpendicular to the shaft, in the tangential direction of the swing. In actuality you need to exert two forces along this axis, one in each direction, one set the axis and one to act around it. There are multiple ways these forces are important:

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The thing is that you are pushing up on one side of the object and down on the other, inducing a large moment into it. You need to resist that moment with your wrist. Take a couple of bars set them on the table and push yourself up on them. You are just pushing down so it should be easy right? Except that you are inducing a moment in the bars and as they are not fixed to the table you have to resist that with your wrist. It goes from easy when you have something to handle the moment to damn near impossible.