Talk:Work (physics)/Archives/2011/November

The article is reasonably complete but messy
It contains practically all relevant statements, and incorrect formulations have been almost all corrected (I have taken the liberty to change/revert the lead sentence on the line integral, see the "Note" below). It can remain "as is" until some systematic rearrangement, which I think should be carried out in order to make it more "smooth", with more logical ordering and with more harmonized notation.

I can agree that the lead presentation of the concept may be limited to simple statements (no "heavy" math) - but then this also should be done systematically. For example, only two leading paragraphs can be kept, with addition of two very "light" notes on power and energy. (In that case, a sentence should be added in the first paragraph saying something like this "In the case that the force is changing, multiplication must be replaced by integration.")

I wonder why the people (are there any?) from the ProjectEnergy (where this article has top importance) or ProjectPhysics (high importance) are not more active in this discussion page. Anyway, I shall leave the article for a while. Perhaps it will attract some more (and more specific) suggestions in the meantime.

Note: I have reverted the line integral sentence to my original version:
 * "Work of a force is the line integral of its scalar tangential component along the path of its application point."

The change made to it was definitely incorrect. For a moment I suspected that my formulation might be an inappropriate rendering into English, but fortunately the wikipedia article on line integral is well written, so let me quote two relevant sentences: (1) (On the line integral of the scalar field f)-"The function f is called the integrand, the curve C is the domain of integration, and the symbol ds may be intuitively interpreted as an elementary arc length." (2) (On the line integral of the scalar thangential component of a vector) - "A line integral of a scalar field is thus a line integral of a vector field where the vectors are always tangential to the line."

Therefore, there is no doubt my original formulation means in English that the scalar tangential component of the force is multiplied by an infinitesimal path element, as it should be. Of course, parametrization of the path can then be introduced, but I do not think this should be included in the definition sentence. However, even if that is done, the paramater does not have to be the time. And if the parameter is chosen to be the time, that should be mentioned (e.g. time integral along the path...); and the force component should be multiplied by speed (of the application point), not by "velocity". QED--Ilevanat (talk) 00:54, 7 November 2011 (UTC)


 * I assume that your statement that you "shall leave the article for a while" is an invitation to others to make revisions. I will try to help with this. Prof McCarthy (talk) 15:53, 7 November 2011 (UTC)

Correct assumption; and, of course, you are welcome (to say the least). And I see this most recent edit as another move in the right direction.--Ilevanat (talk) 21:48, 7 November 2011 (UTC)