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October 4, 2012, 05:44 PM   #22
481
Senior Member

Join Date: April 18, 2011
Posts: 499
Quote:
 Originally Posted by zombietactics: It's not a question of "dismissing" it, rather a point that it's not the important factor in play. You can derive cross-sectional area starting with the radius as well ... it's just an innumerate way to look at the problem.
That is nonsense. Diameter is an important factor in the determination of cross-sectional area. In fact, it is the main determinant since п is nothing more than a constant.

Radius is simply one half of the diameter.

The formula for cross-sectional area is

пr²

or, if you wanna express it terms of diameter

п(½D)²

because r = ½D

Any fourth grader can tell you this.

Either way you must use some function of the diameter of the bullet's expansion face to determine the cross-sectional area of the circular face. For this reason, it is the most important factor in play. You CANNOT determine the cross-sectional area of a bullet without it.

ETA-

If you don't believe me, perhaps you'll take it from here

http://en.wikipedia.org/wiki/Circle

Check out the illustration at the upper right corner of the page in the link.

Can't believe we have to argue such simple matters these days.
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Last edited by 481; October 4, 2012 at 06:00 PM.

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