Talk:Mechanical work

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Help with this template Comments: work/Comments|action=edit}} edit – work/Comments|action=history}} history – work/Comments|action=watch}} watch – work|action=purge}} refresh In case of sign convention used to defin PV work the negative sign is used by mentioning that during the doing work system looses energy but it is only true for Adiabatic process and In case of ISOTHERMAL process the work is done at the cost of supplied heat, therefore there is no question of negative sign and work should have possitive sign.

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Contents 1 Stub tag 2 Move 3 Removal 4 Order of things 5 Redirected Mechanical energy here 5.1 Unmerge? 6 Text copied from other site 7 Simple is better 8 Work is 1/2*m*v^2

[edit] Stub tag

Is this article really a stub? I think it's quite adequate in what it explains, even though it's not really long. Really, how much more CAN you say about work? Perhaps the stub tag should be removed? - Lord Kenneth 03:20, Jan 16, 2004 (UTC)

As in many Wikipedia explanations, many of the most basic notions of this subject are omitted...A middle or high school student for example is taught that work is force times distance and that the units would therefore be newtons times meters...newton-meters and reported in joules which is te unit for work. An up-front explanation of this would have been nice... —Preceding unsigned comment added by 75.105.253.23 (talk) 14:53, 3 October 2007 (UTC)

I agree. Mkweise 23:11, 17 Feb 2004 (UTC)

[edit] Move

I object to your moving Work (physics) to Mechanical work. I was actually just about to perform the reverse move when I discovered your previous action. There are other types of work, such as electrical work (energy lost by a system due to pushing electrons through a circuit). -Smack 00:16, 10 Jan 2004 (UTC)

Electrical work can be reduced to mechanical work, since it involves moving bodies (electrons or ions) against a force (electrical field). Additionally, the term "work" is not usually used outside of Newtonian mechanics - in other fields of physics, one generally speaks of energy rather than work.

That said, I don't feel strongly enough on the matter to make a fuss if you and others prefer "Work (physics)". Mkweise 23:10, 17 Feb 2004 (UTC)

In modern physics, the term energy is generally used to refer to all forms of energy, including mechanical work. -- I don't think this statement is correct. Work is not energy, work is the transfer of energy. Bensaccount 04:06, 23 May 2004 (UTC)

[edit] Removal

I've removed the statement "in the direction of the force" from the introduction. I believe that it is both needlessly confusing for an opening paragraph and inaccurate. You shouldn't say things like that unless you're willing to immediately get into the question of orthogonal components and resolution. --Smack 19:04, 26 Jul 2004 (UTC)

In the UK, the topic of Mechanical Work is often taught before vectors and integration, and well before vector integration. As such, any of my students visiting this page would need to read down as far as Simpler Formulas before they can use scalars in the appropriate context. My addition of the offending phrase was meant for those readers for whom vector integration in the second sentence of an article would be too much.

The Position link leads to a disambiguation page - did you mean this? The Location article looks a slightly better link (still identified as position, of course)

For uniform circular motion, it is usually the angular velocity that is constant. The (vector) velocity changes continuously.

Ian Cairns 00:41, 14 Aug 2004 (UTC)

Have I addressed these issues to your satisfaction? --Smack 19:55, 17 Aug 2004 (UTC)

Looks good to me - but I'm not the referee. Thanks Ian Cairns 21:38, 17 Aug 2004 (UTC)

[edit] Order of things

I think it'd be better, from a pedagogic standpoint, to introduce the notion of work by starting with the simpler cases (currently discussed in the "Simpler Formulae" paragraph), then progessively generalize it, culminating in the full-blown integral form. Ideally, we should insert a few diagrams to illustrate the various formulae.

--Mamour 14:15, 19 Feb 2005 (UTC)

With all due consideration for readers who aren't familiar with multivariable calculus, I think it's still best to state a proper definition up front, or at least to provide a prominent link to one. I've modified the introduction a bit - do you think my change is satisfactory? --Smack (talk) 03:59, 20 Feb 2005 (UTC)

[edit] Redirected Mechanical energy here

Merged material from Mechanical energy into section with the same name. Also edited the article: changed some formulaes to "standard" quantity symbols, added new sub-sections "Definition", "Types of work" and "Conservation of mechanical energy". Removed stub-status, removed "in the direction of the force" (there is no word of this in my two independent school physics books), made som small adjustments to text. But check the "Conservation of mechanical energy" section. I am not completely sure if there is a more general definition to this. Thechamelon 01:07, Apr 21, 2005 (UTC) Re-edited 01:07, Apr 21, 2005 (UTC).

[edit] Unmerge?

I don't think that this merge was warranted. The old mechanical energy stub was a stub not because there was nothing to say on the topic, but because nobody had bothered to say it. For instance, the treatment of conservation of mechanical energy has no place in an article on work. --Smack (talk) 21:28, 23 Apr 2005 (UTC)

I'd disagree. I suggested the merger that Thechamelon has effected - for the reasons mentioned at the top of this Talk page by Mkweise, that work and energy are usually synonymous in modern physics. Of course, it's possible that the equation of work and energy can be clarified further in this article. Thanks, Ian Cairns 21:58, 23 Apr 2005 (UTC)

Hmm.. I would personally prefer to split this article in Work (physics) and Conservation of energy since these two headlines would cover any topic within. I think I could write more on this if it was a more general topic. Furthermore, mechanical work is only a specific type of work in physics. The Work (physics) page could have info on electrical work too. The only reason that I moved it was that it seemed that some wikis wanted to... If I did something I shouldn't (out of guidelines etc.) please tell me. I haven't seen any rule on merging yet? Thechamelon 13:43, Apr 24, 2005 (UTC)

As I understand it, this merge rests on two premises: that work and energy are synonymous, and that energy and its conservation are indistinguishable. In general, this is true, but in the special case of strictly mechanical work, it is not. Mechanical work and mechanical energy are not equivalent, because of the possibility of dissipative forces.

Actually, there's a third premise: that it's not necessary to maintain separate articles on closely related concepts like work and energy. I could argue that each page should be at least a stub, so that it can be properly defined. Redirecting people from conservation of mechanical energy to mechanical work is a bit of a reach. --Smack (talk) 04:38, 26 Apr 2005 (UTC)

[edit] Text copied from other site

I'm not sure on which site did it, but this page is virtually identical with one at http://www.answers.com/topic/mechanical-work

I'm not sure if they copied from us or vice versa, but if its been selected to go into the CD it's worth checking out. —Preceding unsigned comment added by Russellmartin (talk • contribs)

They copied from us. answers.com is one of many Wikipedia mirrors, sites which periodically update themselves with the Wikipedia database. This is perfectly okay. See also Wikipedia:Mirrors_and_forks/Abc#Answers.com. -- Meni Rosenfeld (talk) 13:43, 9 September 2006 (UTC)

[edit] Simple is better

Work is a very important encyclopedia entry. People without math degrees should be able to read this article and easily understand the topic. I just simplified the first paragraph, please don't revert it back to the discombobulated clusterfuck that it used to be.

I just don't understand peoples' desire to make a simple concept more complicated than it is (or needs to be) by piling on excessive technical jargon and unordered random crap. Sullevon 16:30, 16 September 2006 (UTC)

I agree with the edit you made; In a more general context, however, it is often impossible to give a definition which is both simple and correct. An encyclopedia should, IMO, err on the side of correctness. -- Meni Rosenfeld (talk) 16:53, 16 September 2006 (UTC)

I disagree with your sign convention used for PV type work done in isothermal process, because in case of isothermal process the energy is supplied to the system and work is done at the cost of supplied energy, therefore, the work done in isothermal process can not have negative sign.[ User: prof. Rajendra Mandapmalvi,( Email : mandapmalvi@hotmail.com)]

[edit] Work is 1/2*m*v^2

There is an equation in this Wikipedia article that is incorrect. Work is not 1/2*m*v^2, but the change in this quantity. There is a distinction. Anyone care to change it? Also, anyone want to define the variables "m" and "v" for those who have no background in physics? --Armaetin (talk) 07:35, 28 February 2008 (UTC)

The equation is given for the specific case of an object originally at rest - so it is correct as it stands. Later in the article it gives the more general case defining it in terms of the change in kinetic energy. PhySusie (talk) 16:05, 28 February 2008 (UTC)