|
|
Posted for "Paul Davis" <pdavis@bmc.com>:
On Wed, 25 Sep 2002, "Lorn" == Lorn H. Olsen wrote:
Lorn> Thank you for the very clear and understandable post.
Lorn> However, I believe that you have a problem in that the area
Lorn> listed above sould be: PI * r^2. With a 3 inch diameter
Lorn> opening, the wrong calculation leads to an answer 2 times as
Lorn> large as it should be.
Lorn> eg. 1/2 * 3^2 * PI = 14.14
Lorn> and PI * 1.5^2 = 7.07
When I first read what you posted I thought you were saying the area
is 7.07, but I see that the entire expansion is:
0.5 * 3.1416 * 1.5**2 = 0.5 * 3.1416 * 2.25 = 3.5343
Yes?
-------------------
Paul Davis
Lancair Legacy builder
pdavis@bmc.com
Phone 713-918-1550
[Actually, no. The formula says Pi * R^2. If the diameter of the opening is 3", then the formula becomes Pi * (3/2)^2... you can't take the .5 ( /2) factor twice. According to the order of operations rules you do the stuff inside the parentheses first (ie, define the radius), then the powers, so 1.5" * 1.5" = 2.25si.... then multiply out the rest 3.1416 * 2.25si = 7.07si.
<Marv> ]
|
|