- Joined
- Apr 27, 1999
- Messages
- 6,117
Getting down to the physics of throwing knives: E = 1/2 M V^2. The velocity-squared term in the equation says that the kinetic energy of your knife goes up much faster with velocity than with mass. It also has no term related to the length of the knife. Energy is what you need to break the mechanical bonds holding your target together.
The reason you don't go for a one ounce knife is that you can only throw so fast and when you approach your limiting hand velocity your best bet is to make your projectile heavier. Throwing knives, of course, are toys more than tools. The real throwing weapons were javelins. They have a low ratio of weight per length, but an optimum overall weight. I would pick a knife that weighed somewhat less than a javelin as a first choice.
The optimum depends a lot on the weight of your arm and the speed of your muscles. I did my most intense knife throwing practise as a 145 pound teen. The ideal weight for a knife scales a lot with your body weight since the energy of your throw is divided between energy you put into the mass of your arm and the mass of the knife. To find your personal optimum, consider what you personally can throw farther, a softball, a baseball, or a golf ball?
Of course if you had an arm-extending gadget the optimum would to be to go with a lighter projectile going faster. If you have a sling (ala David & Goliath) you can throw a golf ball sized projectile over a hundred yards. If you have a spear throwing stick your best javelin starts to scale down towards arrow size.
The large weight to length ratio recommended for throwing knives supports long distance and imperfect rotation control. A heavy knife that has under-rotated when it hits the target tears a triangular hole like an old style beer can opener. (PS There are basic physical reasons why a knife does not like to rotate edge-on like a saw blade and tends to hit can-opener-style at distance).
So in the end your most reliable throwing knife is going to be pretty heavy relative to your hand weight, but if you're light and fast you can get more performance out of a light knife than you would expect.
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"Defense against knife attack:
Option 1. If you have a gun shoot him."
The reason you don't go for a one ounce knife is that you can only throw so fast and when you approach your limiting hand velocity your best bet is to make your projectile heavier. Throwing knives, of course, are toys more than tools. The real throwing weapons were javelins. They have a low ratio of weight per length, but an optimum overall weight. I would pick a knife that weighed somewhat less than a javelin as a first choice.
The optimum depends a lot on the weight of your arm and the speed of your muscles. I did my most intense knife throwing practise as a 145 pound teen. The ideal weight for a knife scales a lot with your body weight since the energy of your throw is divided between energy you put into the mass of your arm and the mass of the knife. To find your personal optimum, consider what you personally can throw farther, a softball, a baseball, or a golf ball?
Of course if you had an arm-extending gadget the optimum would to be to go with a lighter projectile going faster. If you have a sling (ala David & Goliath) you can throw a golf ball sized projectile over a hundred yards. If you have a spear throwing stick your best javelin starts to scale down towards arrow size.
The large weight to length ratio recommended for throwing knives supports long distance and imperfect rotation control. A heavy knife that has under-rotated when it hits the target tears a triangular hole like an old style beer can opener. (PS There are basic physical reasons why a knife does not like to rotate edge-on like a saw blade and tends to hit can-opener-style at distance).
So in the end your most reliable throwing knife is going to be pretty heavy relative to your hand weight, but if you're light and fast you can get more performance out of a light knife than you would expect.
------------------
"Defense against knife attack:
Option 1. If you have a gun shoot him."