Primitive Archer
Main Discussion Area => Arrows => Topic started by: Deerhunter21 on March 23, 2020, 11:33:48 am
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ok ill try to keep this short.
so I was reading something in the arrows forum and someone said something about a heavier arrow going faster than it should (i dont remember if there was just one arrow that did this or 2). he said something about the arrow being one of the best arrows for that bow. he went on saying how he has no idea how this worked and that it just happened randomly. the difference was about 10 grains (heavier).
so heres what i know
1. this arrow went faster for having more weight
2. it flew amazing on his bow
3. it was the same spine as the other arrows
4. it was basically identical to the other arrows except for weight.
5. the weight was a good bit heavier which should have made it slower but it went faster
so im just wondering, could this have been because of energy transferring to the arrow easier? I learned in school that the heavier (or more mass) a object is/has, the more energy you can put into an object and the longer (or shorter. there is a place where heavy becomes too heavy.) the object will keep the energy.
think about it like this if you have a plastic ball that is super light and you throw it, it will probably go slow and slow down fast because of the wind resistance, gravity, wind, or something like that and fall short. if you have a baseball now thats the same shape and you chuck it the same way (as hard as you can) it will probably go super fast and far because it is able to hold a lot more energy and keep the energy and not be affected by wind, gravity, wind resistance. now what if we have a metal ball, you throw it as hard as you can and the ball goes a ok distance, like a shot put. it went way slower than the plastic ball. the plastic ball went way slower than the baseball.
what i see in that example is a hill on a graph, you add a little weight, the arrow can store more energy = it goes faster (because of the positives of more energy outdo the negatives of it having more weight). you add a little bit more = it goes slower (because the weight now outdos the positive of it having more energy.)
does this make sense? im not good at explaining stuff.
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Some comments:
1. What you are describing is called momentum. I watched a youtube video (the source of all authority) where a guy was experimenting with arrow weight. over relatively long distances, he found his heavier arrows actually hit higher on the target. So while F=MA means the heavy arrow coming off the bow is probably going slower, its added mass means it will be less susceptible to drag due to wind resistance. It should also penetrate deeper into the target because it is harder to slow down Also, a heavier arrow will more efficiently transfers the force of the bow into forward motion, even if at some point the final acceleration MUST be less because of Newton's second law F=MA.
2. Therefore, my lighter arrows clearly move faster coming off the bow than my heavier ones (although I don't have a chrono, so it is all perception) might indeed be more accurate, better for hunting.
3. Your example with the three balls is right on the money.
4. Archery is all about applied physics. You could teach a whole class around it.
5. I like how you are still young enough to use the word "chuck" and get away with it.
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If you want check out Dr. Ashbys' testing and findings.
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I think you're on the right track, Russell.
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I wonder how far he was from the chronograph. if he was too far maybe resistance already took ahold on the lighter arrow slowing it down but the heavier arrow kept its speed. this makes a lot of sense because while the initial speed of the lighter arrow would be faster, the speed at 5, 7, 9, 15, 20, etc (just examples) the lighter arrow would slow down to a point where the heavier arrow would be faster because the lighter arrow would have had more trouble with wind, wind resistance, and stuff like that while the heavier arrow wouldn't have.
ill check it out Ed.
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Understanding momentum like jeff said and KE is good to know.
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Also until you shoot with a shooting machine there are too many variables to accurately say for certain which arrow is doing what.