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Posted: Sun Dec 14, 2008 8:15 am |
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| dummyracer36 |
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| whats the equation to determine fpe? |
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_________________ "not tonight dear, i have a race in the morning" |
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Posted: Sun Dec 14, 2008 8:58 am |
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| Slavia |
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FPE=(v)*(v)*(m)/450240
v=velocity in feet per second
m=mass in grains
So that's mass times velocity squared, all divided by 450240. The constant is for lead projectiles; any other material would have a different number.
You can also use the forum calculator (called "energy and measurement calculators" on the home page):
http://www.airgunhome.com/pages/calculators.html
Happy calculating. |
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Posted: Sun Dec 14, 2008 8:59 am |
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| dummyracer36 |
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_________________ "not tonight dear, i have a race in the morning" |
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Posted: Sun Dec 14, 2008 12:30 pm |
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| rsterne |
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Actually, mass is mass, be it lead or feathers....
The constant is the same, regardless of the material....
Bob |
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Posted: Sun Dec 14, 2008 12:57 pm |
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| AirGunEric |
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Posted: Sun Dec 14, 2008 1:05 pm |
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| Slavia |
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What could I have been thinking! I probably got confused converting from grains to pounds to slugs to grams and then factoring in the inverse hyperbolic integral of the cosmic ray vector (on alternate Tuesdays).
Sorry, it won't happen again. You're right; mass is mass.
http://en.wikipedia.org/wiki/Muzzle_energy |
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Posted: Sun Dec 14, 2008 2:24 pm |
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| cw |
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Last edited by cw on Fri Jan 23, 2009 9:08 pm; edited 1 time in total |
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Posted: Sun Dec 14, 2008 6:15 pm |
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| Jaxom |
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OY!!! and I told my mother and teachers in highschool I would never need to know algebra!!!!  |
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_________________ .22 2300kt Crosman Custom |
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Posted: Sun Dec 14, 2008 7:06 pm |
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| fritz |
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| Jaxom, who says you have to do it? Use a calculator. |
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_________________ "I never set out to be wierd, it was always everyone else who called me it" -Frank Zappa
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Posted: Sun Dec 14, 2008 7:58 pm |
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| Slavia |
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| Quote: |
There is implied mutiplication between adjacent variables
(such as M and V). |
You're correct, of course, and I knew that.
These days it's hard to know where a person's ability lies - be it "pure" algebraic notation, calculator notation, spreadsheet notation, whatever. I threw in the extra punctuation (and the verbal explanation) to increase the probability that the formula would be successfully applied. |
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Posted: Sun Dec 14, 2008 8:36 pm |
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| yourdaddyjoe |
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| Slavia wrote: |
| Quote: |
There is implied mutiplication between adjacent variables
(such as M and V). |
You're correct, of course, and I knew that.
These days it's hard to know where a person's ability lies - be it "pure" algebraic notation, calculator notation, spreadsheet notation, whatever. I threw in the extra punctuation (and the verbal explanation) to increase the probability that the formula would be successfully applied. |
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Posted: Mon Dec 15, 2008 5:31 am |
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| broommaster2000 |
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Posted: Mon Dec 15, 2008 6:19 pm |
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| Jaxom |
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Fritz,
In order to use the calculator, I need to know what the alphebet soup stands for. |
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_________________ .22 2300kt Crosman Custom |
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