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Old 01-15-2006 | 12:13 PM
  #8  
Sylvan
Nontypical Buck
 
Joined: Jan 2005
Posts: 2,435
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From: Upstate New York
Default RE: Agree or disagree???

It is possible to go over the arrow weight that will shoot most efficiently from your bow. If you shoot a variety of arrow weights througha chronographand KE keeps climbing, then drops off when you hit a certain weight, then you know you've gone beyond your bow's peak efficiency range. The ol' bell curve in action. I'd stop at the top of the curve.
The function here is not a bell shapedcurve.Dynamic efficiencyincreases with arrow mass.

Here's the proof.

SE = Stored energy
KE = Kinetic energy
v = velocity
m1 = mass of arrow
m2 = virtual mass

SE = 1/2(m1 + m2) v^2
Therefore:
v=((2SE/(m1+m2))^1/2

and:
KE = 1/2m1v^2
Therefore substituting ((2SE/(m1+m2))^1/2 for v and reducing:
KE=m1SE/(m1+m2)

Now as anyone can see, as m1 is multiplied by SE in the numerator and m1 is only added by m2 in the denominator it isclear that as m1 increases KE increases as well. Now as SE is a constant for a given bow setup as KE increases with arrow mass then so does efficiency.

You can't cheat the physics! Dynamic eff increases linearly with arrow mass. Virtual mass modifies the slope of the function.
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