Throwing Knife Physics: Why Blade End Hits More Often

In summary, when a throwing knife is thrown, it hits its blade end due to the spin and center of mass of the knife being towards the point end. This is also affected by the thrower's skill and technique, as well as adjustments made for distance, angle of release, and rotation of the wrist. Variations in throw technique can improve accuracy and range, and throwers may also have to adjust for obstacles such as corners or trees. Ultimately, successfully throwing a knife requires a combination of skill, technique, and understanding of the basic principles of mechanics.
  • #1
Aditya3003
7
0
When a throwing knife is thrown why does it only hit its blade end ( not the grip end)? The knife has been imparted with a spin and there is a 50:50 probability that its blade end will hit (actually a bit less).
It would be better if you explain assuming the blade's CM has velocity 'v' and is imparted with an angular velocity ω and its target is at distance 'd' if the explanation is complicated.
I think it is because the knife only spins once and the brain automatically calculates the angular velocity which needs to be imparted.
 
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  • #2
My understanding is that this happens primarily because the center of mass of the knife is towards the point end. As it moves right up close to the target, either the last rotation causes it to stick (by the point), OR it causes the handle to not hit the target and there is then another revolution that embeds the point.

EDIT: and by the way, they DON'T always stick by the point. Bad timing can occur and they bounce off, so part of the explanation is the skill of the thrower.
 
  • #3
Wikipedia- http://en.wikipedia.org/wiki/Knife_throwing#Basic_principles
Knife throwing, whether in a martial or sport application, involves the same basic principles of mechanics. The objective in each case is for the point to stick into the target with a sufficient amount of force. For this to be successful, accuracy, distance, number of rotations and placement of the body all must be taken into account unless a no-spin technique is employed by the thrower (there are spin and no-spin throwing techniques). If the thrower uses a spin technique, the knife will rotate during flight.[1] This means that the thrower, assuming he is throwing the same way every time, must either choose a specific distance for each type of throw or, more practically, make slight adjustments to placement of the knife in the hand as well as angle of release and rotation of the wrist. Variations in throw technique can allow great accuracy and range. Throwers may also need to adjust for throwing off-center, around corners, and while running.
 
  • #4
I used to play with throwing knives a lot last summer and the blade doesn't always hit your target. I've gotten the handle stuck in a tree before. You have to learn how to throw them. There is a certain distance:rotation ratio you have to follow
 
  • #5
 
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  • #6
Around corners? Cool!
 

1. How does the shape of the knife affect its accuracy?

The shape of the knife plays a significant role in its accuracy. A throwing knife with a straight blade is more likely to hit with the handle end because the center of mass is closer to the tip. On the other hand, a knife with a curved or tapered blade has a more evenly distributed mass, making it more likely to hit with the blade end.

2. What role does the weight of the knife play in its accuracy?

The weight of the knife also affects its accuracy. A heavier knife will have more momentum and will be more likely to hit with the blade end. However, a lighter knife requires less force to throw and can be more accurate with proper technique.

3. Can the throwing technique impact the likelihood of hitting with the blade end?

Absolutely. The throwing technique is crucial in determining the accuracy of a throwing knife. Proper grip, stance, release, and follow-through can all affect whether the blade or handle end hits the target.

4. Are there other factors besides the knife itself that can affect the likelihood of hitting with the blade end?

Yes, environmental factors such as wind, distance, and target size can also impact the accuracy of a throwing knife. Wind can alter the trajectory of the knife, while a longer distance and smaller target can make it more difficult to hit with the blade end.

5. Is it possible to consistently hit with the blade end using only physics principles?

No, while understanding the physics behind throwing knife accuracy can improve your chances of hitting with the blade end, it does not guarantee consistent results. Factors such as individual technique, environmental conditions, and variations in knife design can all affect the outcome. Practice and experimentation are necessary to achieve consistent results.

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