Talk:Work (physics)

What about the other sort of work?

Any plans on how to disambiguate from the other sort of work - you know, the boring kind that we all have to do. –Tom Morris 08:29, 3 July 2009 (UTC)

Yes, I made a mistake, I will move.--Paul Wormer 09:52, 3 July 2009 (UTC)

Lead should be in everyday language understandable by the target reader.

It seems to me that the definition of work, along with examples, should be given and explored in the lead before the math is entered into the balance of the article. I took the liberty of demonstrating what I mean in the rewritten lead, as you can see. Not being a physicist, I used the examples that sprang to mind to explain the subject. If they fall off the mark, they can certainly be changed, but I hope the CZ community agrees that the introductory section, at least, should be written in plain English. Sincerely, your friend, George Garrigues 07:36, 5 July 2009 (UTC)

I hope that more articles on "work" will appear (economic, sociological, etc.) together with a disambiguation page (like energy). It seems to me that George's lead would be more appropriate either in the disambig or in the sociologically oriented article. Note that the title (physics in parentheses) narrows down the present article considerably. To me the comparison of a force in physics with the "police force" [which BTW only works (no pun) in English] is a bit far fetched in the context of a physics article.--Paul Wormer 09:26, 5 July 2009 (UTC)

On second thought, I started a disambiguation page and moved George's lead-in to there, and reverted the present page. I reverted because George removed the (for a physicist essential) sentence about the dimension and units used for "work (physics)" and removed also the essential adjective "magnetic" (non-magnetic particles do not align along a magnetic field). --Paul Wormer 09:53, 5 July 2009 (UTC)

Negative work isn't limited to physics; I've had several managers good at negative work. See Dilbert. Howard C. Berkowitz 02:10, 6 July 2009 (UTC)

Yes, in Holland we see coworkers and contraworkers (the latter often spotted among flocks of civil servants).--Paul Wormer 06:04, 6 July 2009 (UTC)

Britanica text

On the whole we, at CZ, see the Britanica as our role model. The Britanica gives the following for "work" (note its readability or lack thereof):

in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force at least part of which is applied in the direction of the displacement. If the force is constant, work may be computed by multiplying the length of the path by the component of the force acting along the path. Work done on a body is accomplished not only by a displacement of the body as a whole from one place to another but also, for example, by compressing a gas, by rotating a shaft, and even by causing invisible motions of the particles within a body by an external magnetic force.

No work, as understood in this context, is done unless the object is displaced in some way and there is a component of the force along the path over which the object is moved. Holding a heavy object stationary does not transfer energy to it, because there is no displacement. Holding the end of a rope on which a heavy object is being swung around at constant speed in a circle does not transfer energy to the object, because the force is toward the centre of the circle at a right angle to the displacement. No work is done in either case.

The mathematical expression for work depends upon the particular circumstances. Work done in compressing a gas at constanttemperature may be expressed as the product of pressure times the change in volume. Work done by a torque in rotating a shaftmay be expressed as the product of the torque times the angular displacement.

Work done on a body is equal to the increase in the energy of the body, for work transfers energy to the body. If, however, the applied force is opposite to the motion of the object, the work is considered to be negative, implying that energy is taken from the object. The units in which work is expressed are the same as those for energy, for example, in the metre-kilogram-second system, joule (newton-metre); in the centimetre-gram-second system, erg (dyne-centimetre); and in the English system, foot-pound.

--Paul Wormer 06:33, 6 July 2009 (UTC)

Thinking out loud about "lay" versus physics"

I don't pretend to have a solution, and fully understand that you are using work in a specific physics context. Here are, however, a few thoughts. The first, second, and fourth paragraph in the "History" section might be paraphrased into the lede.

Also, more of a graphic rearrangement might help. I don't know if you've ever seen the "New Mathematical Series", but they do an amazing job of introducing, for bright high school students, concepts that I'd otherwise assume are advanced undergraduate for math majors. Their approach is to stay graphical rather than going immediately to proper mathematical notation.

Your first diagram, showing vectors, might well be discussed in a narrative way, arranging the text and equations so there's a paragraph or two discussing it informally before the reader sees the first integral equation. Howard C. Berkowitz 14:02, 6 July 2009 (UTC)

No I have never seen the "New Mathematical Series", how could I?

I'm puzzled by your statement

Your first diagram, showing vectors, might well be discussed in a narrative way, arranging the text and equations so there's a paragraph or two discussing it informally before the reader sees the first integral equation.

All of section 1 is discussion of the figure, no integral in sight. I only assume in this section that readers know what the length of a vector is and the definition of a cosine. If I would go to a lower level then the article would degenerate in babble without any content or information (what, BTW, seems to be the preference of lots of readers). The example in section 2 also does not contain any integral. The more mathematical stuff is in section 3. I targeted this section to, say, second or third year undergraduate physics students. --Paul Wormer 15:13, 6 July 2009 (UTC) PS I write of of "an old-fashioned cannon" and "gun powder" explosion, could I phrase this better?--Paul Wormer 15:15, 6 July 2009 (UTC)

I made some tentative moves of histroy that I think might be useful in the introduction; feel free to revert, incorporate, etc.

If I may, I'd like to speculate about the audience. There's little here that I would not have understood in my honors high school physics class, except perhaps some of the later integrals. (actually, my teacher slipped them in, but only told us we were doing "calculus" after we were comfortable.) Nevertheless, "work" is what I would consider a high school or first year undergraduate subject, not second or third year. In the U.S., first year college physics is often offered in two sections, one with a year of calculus as a prerequisite, and the other assuming elementary calculus is being taken simultaneously. Second or third year aspects may be more appropriate for an advanced subpage. Howard C. Berkowitz 15:41, 6 July 2009(UTC)

Of course, sections 1 and 2 are high school stuff. A good understanding of section 3 requires some mathematical maturity, more than the average (organic) chemist possesses. But CZ is not paper, it doesn't hurt if it is there, no overfull book cases! And if somebody doesn't want to know about path integrals then she skips it. Easy. Cutting the history into two made the story somewhat inconsistent. I tried to fix it. --Paul Wormer 16:34, 6 July 2009 (UTC)

Rename to Work (physics) ??

Paul, would you mind if I moved (renamed) this article to Work (physics) instead of the current Work (Physics)? Using a lower case p instead of a capital P would make it consistent with other article titles such as Power (physics), Watt (unit), Energy (science) and Density (chemistry). Milton Beychok 05:37, 23 January 2010 (UTC)

No problem, go ahead. --Paul Wormer 12:19, 23 January 2010 (UTC)

Done. Milton Beychok 16:33, 23 January 2010 (UTC)