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ORIGINAL: HuntingEd

Jeff think about it this way:
Energy is the ability to do work, which is force times distance (F*ds).
Momentum is defined as mass times velocity (m*v).
Mr Isaac Newton discovered in his second law of motion that force is equal to the rate of momentum change with time, F=m*dv/dt, for constant mass. Now since distance ,ds, = v*dt, and incremental KE of motion = F*ds, then substituting, KE= (m*dv/dt)v*dt = m*v*dv. Integrating , KE=1/2m*v squared.

:D

In other words. KE ismore important!!

Think about this, you have 1000lb truck moving at1 f/s, and a 1 lb baseball moving at 1000 f/s. Which would you rather get hit buy??

I hope you answered the truck.

Momentum Truck = 1000
Momentum Ball = 1000

KE truck = 500
KE Ball = 500,000!!!!


Now take this to an arrow and its purpose. How does an arrow due its damage? It CUTS during penetration. IT doesnt create damage through blunt impact like a bullet.

Higher KE gives you Higher penetration because KE is ability to do work (ie. damage),

IMO, I'll take more KE because it gives you more energy to cut through bone and tissues. Becase I rarely make a perfect shot between the ribs.


Do a test. Shoot a 100 grain tip at your target. then a 125.

See which one penetrates deeper, it will be the one w/ more KE.

You also need to take into account that more mass increases the storage of energy :) the amount of energy you bow can produce doesnt change, so a lot of energy is lost on a light arrow due to noise, vibration etc. So more often than not a heavier arrow will have higher momentum & KE because of this.

But you then trade off the ablity to shoot flat! So its personal preference.

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ORIGINAL: HuntingEd


Think about this, you have 1000lb truck moving at1 f/s, and a 1 lb baseball moving at 1000 f/s. Which would you rather get hit buy??

I hope you answered the truck.

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25 grains probably is not going to slow it down much at all. I changed an arrow by adding 70 grains to the total weight and the speed only slowed by 13fps.

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ORIGINAL: Germ

Where Quick is correct is KE is KE
70 lbs KE on a Quick 285 grain arrow is the same as 70 lbs KE on my 525 Grain Arrow.

The only differnce is a stiff breeze with blow quicks arrow to MI. This is where today's faster bows come into play. Bows waste energy, the heavier arrow the less energy wasted. I have always wondered what the "best" arrow setup would be on a setup.

The arrow weight that gives you the most KE/speed/momentum?

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ORIGINAL: JoeRE

That is 100% correct, but now lets answer it from an archery perspective. Take that force generated by the truck....and the force generated but the baseball....and concentrate them both in an area the diameter of an arrow. Both of them will kill you. Thats why that example doesnt mean anything when you are talking about a 600 grain arrow flying at 200 fps and a 300 grain arrow flying at 300 fps. Truth is, they both will do the trick. Which one penetrates better? One's got more KE....the other more momentum. I pick one, you pick the other....they both still do the trick.

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ORIGINAL: jackflap

I lost 8fps with just 25 gr addition. Not doubting you at all. Just makes me realize that I must have an antiquated and/orwimpy set up. I do shoot an older bow and should I dare say a Matthews.:D

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I have always wondered what the "best" arrow setup would be on a setup.

The arrow weight that gives you the most KE/speed/momentum?

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Its all PERSONAL PREFERENCE, although we have to come up w/ a formula that shows the optimum set-up. IE where you get a lot of KE w/ great speed...

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When I went from a lighter arrow to the 533gr arrow my bow's energy transfer efficiency went up.

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