Talk:Couple (mechanics)

couple = torque ?
I think couple = torque. Isn't it? --Saippuakauppias ⇄ 21:25, 10 June 2008 (UTC)
 * They are not strictly equivalent - torque is the moment resulting from the application of a couple. A torque can result from a single force or a combination of different forces. A couple can only result from two equal and opposite forces. –Sarregouset (talk) 00:48, 2 November 2008 (UTC)

is force mandatory for moment
The principal states sum of moments has to add up, does it imply there has to be a force coupled with a moment? In other words there can simply exist a moment without a force is it not? Typically we tend to associate a force with a twisting moment because things have to add up but is there any such statement ever made? (i.e a twist/moment has to have an associated force? I have seen this break in case of cantilevers and seen a nice article on Varignon's theorem here: http://web.mit.edu/4.441/1_lectures/1_lecture10/1_lecture10.html but never the reverse) (-Alok 08:29, 29 March 2011 (UTC))

Exam definition of 'couple'
A colleague of mine said that a chief examiner (in the UK) has declared the official definition of a couple to include the fact that the perpendicular distance of each force to the pivot must be the same. Is this true? If it is, can it be clarified on this page (there is mention to a couple producing no change the the momentum of the centre of mass, but does that necessarily mean that the perpendicular distance between the two forces and the pivot must be the same? Plain English would help here I think)  Ph ys ic s and shiz (talk) 11:53, 25 May 2012 (UTC)


 * The textbook by Kane and Levinson is not consistent with that:
 * "A couple is a set of bound vectors (see Sec. 4.1) whose resultant (see Sec. 4.1) is equal to zero. A couple consisting of only two vectors is called a simple couple. Hence, the vectors forming a simple couple necessarily have equal magnitudes and opposite directions."
 * i.e. the exam may be using "couple" to mean "simple couple". Don't know about other textbooks. --Steve (talk) 02:34, 28 May 2012 (UTC)

what does it mean?
-Abhishek Shukla.. paragraph — Preceding unsigned comment added by 132.69.194.217 (talk) 09:22, 5 July 2017 (UTC)

Something got messed up in the formula
Something got messed up in the formula at 'Simple Couple' 'Definition' where 'd' was supposed to be defined - fix please thanks 12.33.223.210 (talk) 23:09, 5 February 2019 (UTC)
 * Done. Dger (talk) 00:34, 6 February 2019 (UTC)

Double couple?
The article discusses a simple couple (which is perhaps equivalent to a single couple?), but makes not mention either single- or double-couple. Could someone add a description of those? &diams; J. Johnson (JJ) (talk) 22:07, 13 February 2019 (UTC)