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## Re: [uom-ontology-std] What is mass?

 To: "uom-ontology-std" "ingvar_johansson" Tue, 29 Sep 2009 17:22:55 +0200 (CEST) <63477.83.254.150.253.1254237775.squirrel@xxxxxxxxxxxxxx>
 ```Dear Joe,    (01) Jump to the end of the mail; there is my responsse.    (02) > ingvar_johansson wrote: > > > > Here comes the only passage where the SI brochure mentions 'torque' > (pp. > > 119-20): > > > > "In practice, with certain quantities, preference is given to the use > of > > certain special unit names, or combinations of unit names, to > facilitate > > the distinction between different quantities having the same dimension. > > When using this freedom, one may recall the process by which the > quantity > > is defined. For example, the quantity torque may be thought of as the > > cross product of force and distance, suggesting the unit newton metre, > or > > it may be thought of as energy per angle, suggesting the unit joule per > > radian." > > > > Ingvar > > Excerpted from my copy of ISO/DIS 80000-1, "Quantities and units" > -----------snip--------- > 3.2 > kind of quantity > aspect common to mutually comparable quantities > > NOTES > > 1 — The division of the concept ‘quantity’ into several kinds is to some > extent > arbitrary. > EXAMPLES > a) The quantities diameter, circumference, and wavelength are generally > considered to be quantities of the same kind, namely, of the kind of > quantity > called length. > b) The quantities heat, kinetic energy, and potential energy, are > generally > considered to be quantities of the same kind, namely, of the kind of > quantity > called energy. > > 2 — Quantities of the same kind within a given system of quantities have > the > same quantity dimension. However, quantities of the same dimension are not > necessarily of the same kind. > EXAMPLE > The quantities moment of force and energy are, by convention, not regarded > as > being of the same kind, although they have the same dimension. Similarly > for > heat capacity and entropy, as well as for number of entities, relative > permeability, and mass fraction. > > 3 — In English, the terms for quantities in the left half of the table in > 1.1, > Note 1, are often used for the corresponding 'kinds of quantity'. In > French, the > term “nature” is only used in expressions such as “grandeurs de même > nature” (in > English, “quantities of the same kind”). > > > -----snip------ > > > torque being "moment of force" > > > n.b. - Units alone are not sufficient for determining "comparable > quantities".    (03) I am as aware of the contents of VIM as of the SI brochure, and your "n.b." makes exactly my point. What you might call "newton-meter as a unit alone", I prefer to call "nominal newton-meter". However, note that only some units can be called nominal units and tied to more than one kind-of-quantity; many units are unambiguously tied only to one kind-of-quantity.    (04) Ingvar    (05) > > jbc > > -- > _______________________________ > Joseph B. Collins, Ph.D. > Code 5583, Adv. Info. Tech. > Naval Research Laboratory > Washington, DC 20375 > (202) 404-7041 > (202) 767-1122 (fax) > B34, R221C > _______________________________ > > _________________________________________________________________ > Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/ > Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx > Config/Unsubscribe: > http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/ > Shared Files: http://ontolog.cim3.net/file/work/UoM/ > Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard > >    (06) _________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/ Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/ Shared Files: http://ontolog.cim3.net/file/work/UoM/ Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard    (07) ```
 Current Thread Re: [uom-ontology-std] What is mass?, (continued) Re: [uom-ontology-std] What is mass?, ingvar_johansson Re: [uom-ontology-std] What is mass?, Chris Partridge Re: [uom-ontology-std] What is mass?, ingvar_johansson Re: [uom-ontology-std] What is mass?, Joe Collins Re: [uom-ontology-std] What is mass?, ingvar_johansson Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, ingvar_johansson Re: [uom-ontology-std] What is mass?, Joe Collins Re: [uom-ontology-std] What is mass?, Pat Hayes Re: [uom-ontology-std] What is mass?, Joe Collins Re: [uom-ontology-std] What is mass?, ingvar_johansson <= Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, Martin S. Weber Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, Martin S. Weber Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, Joe Collins Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, Matthew West Re: [uom-ontology-std] What is mass?, Gunther Schadow Re: [uom-ontology-std] What is mass?, Chris Partridge