Sorry for the misunderstanding

Well I caught it. Your KE formula is for standard Kinematics. This one is used for arrows

KE=(mv²)/450,240

Ya, I remembered when I was getting the conversion factor into excel, and I was half of teh 450240 number. A little light went, "duh". Anyway, I will have to play tonight and see what info a spreadsheet gives and how it all lays out.

I read that story too and they are wrong. As soon as an arrow loses the push of the string, it starts to slow down. If i want penetration, at any distance, im going to shot the heaviest arrow i can find. Reason 1. A drop in speed of 50 fps of a heavy arrow changes the momentum less the lighter the arrow. 2. the heavier the arrow the more efficient the bow is. Just my thoughts.

Very possible! I just grabbed a handfull of alluminums to screw around. My bow wasn't tuned to them at all. Although they appeared to be hitting the target straight you guys are probably correct. I guess it shows the importance of tuning your bow to your arrows , especially for hunting penetration.

Here is something that I don't think was discussed! It just popped into my head and I am not sure, so bear with me.

As the arrow is leaving the bow, the string is forcing the arrow forward while the air is actually pushing it back!

Now, my thought is this..... where is the majority of the force on the arrow. As soon as it leaves the string, it would seem that most of the energy in the arrow would be towards the back, as there is not a physical force pushing it anymore. Now, as it goes towards the target, wouldn't the FOC mean that the energy would move towards the front of the arrow, which it seems would mean that penetration would increase. Like I said, I am not sure about this, but it is a possability as to why people notice better penetration at further distances!

Now, as far as arrow weight goes. I have always used the analogy of which would you rather be hit with, a bowling ball going 10 mph, or a ping-pong ball going 100 mph! Sure, it is "far fetched", but it is one way of thinking. A heavier arrow is going to carry more momentum, and that momentum is what gets the arrow through the deer. Like others have said, a heavier object is going to be harder to stop than a lighter object.

Nope, all the energy is equally distibuted. It is not concentrated at the back of the arrow. Maybe this would be possible if 99.9% of the mass of the arrow was concentrated at the back, but I don't think an arrow like that would fly so great.[8D]

That ping pong ball would have to be going A LOT faster than 100mph for those two to be anywhere near comparible. THat ping pong ball is a lot less that 1/10 the mass of the bowling ball. Good idea though, I can see your point.

Buck Magnet, you're opening a can of worms I don't think anyone understands. Certainly not ME. [&:]

I've tried to visualize what happens during the release, when force is being applied to the nock end of the arrow while the arrow's inertia is resisting that force. I know the force isn't distributed along the full length of the arrow all at once because an arrow is not absolutely rigid. The nock end starts moving just a splintered second before the point, the point is the last part of the arrow to surrender it's inertia, so the arrow is forced to flex (paradox). How much the arrow flexes depends on how much force is applied, shaft stiffness, tip weight and how directly inline, from nock to point, that force is applied (straight and level nock travel).

As a fingers shooter, I know my string is not going to apply force to the arrow nock anywhere near straight. So, I have to pick a stiffer arrow than someone shooting a release; I have to adjust my centershot to compensate for the lateral displacement of the string when it goes around my fingertips; I have to use more surface area for my fletching; I have to use a somewhat higher FOC. All those combined will help minimize paradox, send the arrow in the direction I want it to go AND stabilize the arrow as soon as possible.

When the arrow leaves the string, the energy is distributed throughout the arrow's length but the arrow shaft has not stabilized to put the energy in the nock end directly behind the energy in the point end. Until that arrow completes paradox, stops flexing, and settles down into a straight line, some of the arrow's energy is going to be offset from the point.

You ever watch slo-mo video of Byron Ferguson shooting aspirins out of the air with his longbow? It's amazing how much the arrow is flexed when it hits those aspirin.

Anyway, back to the point, energy and momentum transfer from back to front occur during the release. By the time the arrow has left the string, that stuff is fully distributed along the arrow shaft. It's how that energy is aligned that's important.

Might be totally wrong, but that's the way I imagine it works.

As I understood that, the arrow did not even come off the bow.

BM,

Let's flip flop that now. Would you rather be hit with a baseball going 100 mph or a bowling ball going 10 mph?