Talk:First moment of area

Is the "First moment of area" the same as "Centroid"? ...or what is the difference?—The preceding unsigned comment was added by 137.222.120.137 9:45, 1 May 2007 (UTC)).

The difference between the First moment of area and Centroid only become clear when when you move away from Real space. Centroid is a term that is, I believe, only defined for the Euclidean Plane and for Euclidean 3-space. The first moment of area is a more general term that applies to other, more abstract spaces that are not intuitive, or that even exist anywhere but in the realm of mathematics. They are the same in Euclidean Space, but should not be combined. Clifsportland (talk) 20:36, 5 June 2010 (UTC)[reply]

First moment of area is equivalent to the distance from the neutral axis to the centroid of the area times the area.?—The preceding unsigned comment was added by BishopUser 19:15, 1 May 2007.

I think the "Definition" section would be much clearer with a diagram showing the area that dA refers to, along with the x-axis. Conceptually, I find this hard to get to grips with (and I did physics at university!). —The preceding unsigned comment was added by 194.176.105.40 08:57, 3 May 2007.

SteveMc 19:46, 5 November 2007 (UTC)[reply]

This page needs some graphics to help understand these concepts. If I have time I will try to create and upload them. SteveMc 14:36, 7 November 2007 (UTC)[reply]

Comment #2

I provide graphics and a better explanation of the graphics on my web site http://www.engineeringaerospace.com/solid_mechanics/first_moment_of_area/index.shtml however because I'm the publisher of that site, I am not allowed to list it under "External Links" here. I believe this is unreasonable because the site has helped a lot of people in past because it's easy to understand and flows logically. If anyone believes this site should be included in this wikipedia page, please list it under external links. Nebojsapajkic (talk) 23:54, 1 February 2009 (UTC)[reply]

Statical Moment... (does anybody really talk like that?)

Fake English? I've never heard the term 'statical moment'. Grammatically and phonetically, it doesn't even sound like it's supposed to be a word in the English language. I've no qualms about leaving it up if it's actually used by anybody, but it seems that the "static moment" is the appropriate term. Any thoughts? Clifsportland (talk) 20:29, 5 June 2010 (UTC)[reply]

Symbols

${\bar {x}}$ and ${\bar {y}}$ aren't defined. If they are meant to be averages, then the expression is incorrect. If they are meant to be vectors, then A must be defined as a vector\tensor.