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It seem interesting to define a quantity that can be directly measured in terms of a quantity that cannot be directly measured and may just be a mathematical convenance.-- 208.54.14.122 ( talk) 08:35, 3 July 2010 (UTC)
PatrickandBrenda 03:10, 11 August 2007 (UTC) In the United States, which is the primary user of the pound-force, the pound-force is almost universal in its application to industry and throughout daily life. I challenge anyone to reasonably argue
"In most daily contexts in the United States, the term “pound” refers unambiguously to a unit of force. Bathroom scales intrinsically display weight or force. An important note, all scales read force as only a balance such as used in a doctor's office can determine mass. A truck carrying one-thousand pounds of wood refers to the weight or force the wood exerts on the truck. At a local grocery store, one pound of meat will refer to the force or weight of the meat, and may even be weighed using a scale at the meat counter..."
I also challenge people who oppose this to present common everyday uses or pound-mass (other than niche industry uses).
The pound force has historically and continues to be today the primary use of the word "pound." As a Senior Mechanical Engineer for Westinghouse Electric Co. (Other employers include Terex Corp. and Emerson Process Management among others) I have never encounter a company (outside steam power plant designers) that ever (used in the literal sense) use pound-mass.
I think a lot of this discussion is missing the point about the pound-f in the system of units. It is entirely true that people have used force and mass interchangeably in the popular setting because a pound of mass produces a pound of force in Earth's gravity where most people experience it. However, there are other units to be considered here. What about the FPS units for energy? -- ft-lbs. Energy must be a distance multiplied by a force, not by a mass. So a pound-mass may be the common and legal/commercial definition, but for the rest of the system to be coherent, lb-f needs to be used. ArkianNWM ( talk) 19:37, 24 April 2009 (UTC)
Will you guys stop this edit warring and find a cite to settle the matter? , revert... It's not like this is a matter of opinion or anything. -- Yath 07:41, 19 August 2007 (UTC)
I don't see reverting patent nonsense as edit warring. You don't have to look very far for a ref--try slug (mass). This statement:
"One pound-force is the force equivalent to that exerted on a mass of one slug accelerated by gravity on the (idealized) surface of Earth or one avoirdupois pound at an acceleration of gravity divided by the universal gravitational constant."
is false. A pound (force) is the amount of force exerted by gravity on a pound (mass). That's why it's called that. The idea that the universal gravitational constant is involved is absurd. The units don't even work out. Rracecarr 15:39, 19 August 2007 (UTC)
The acceleration due to gravity is given to an absurd number of decimal places, given that it varies from place to place. In fact, this article generally uses too many significant digits. Even when your numbers are exact (or of arbitrary precision), it just looks bad.
Also, pound-force is the common unit, not pound-mass. Sure, you can generally get away without making a distinction, which is why some people get confused, but ask any scientist or engineer, and they will tell you that "pound"--unqualified--means pound-force. If you don't believe me, [1] —Preceding unsigned comment added by 141.219.154.178 ( talk) 16:32, 14 November 2007 (UTC)
Someone has changed the GravEngAbs (Three approaches to mass and force units) box in the Foot-pound-second systems of units section. You can even see the error within the link: Grav = Gravitational; Eng = Engineering and Abs = Absolute! It was correct last week (21 JUL 10). Also check the English Engineering Units page it has the correct units of measure. This week the Engineering heading is switch with the Gravitationl heading. The Engineering system is non-coherent: . The Gravitationl system is coherent: .
Can someone fixs this error? I tried and don't know how to access the original box. Greg Glover ( talk) 23:27, 27 July 2010 (UTC)
Whom ever redirected FPS here has made a grave mistake. The pound force is only found in two of the three subsystems. The system is called the Foot-Pound-Second System or FPS.
Worthington from Great Britain ( http://www.archive.org/stream/dynamicsofrotati00wortiala#page/8/mode/2up) gives two of the subsystems as, Gravitational or Engineer’s and Absolute. Obert from the United States gives the three subsystems as Technical, Engineering, and Absolute.
It is clear to me that the Foot-Pound-Second System should have its own page. A disclaimer could be made until someone finds a reference.
Further, I think this is why someone tampered with the GravEngAbs box. The three systems are, if deduced by both Worthington and Obert and applied here at Wikipedia as:
Otherwise:
Greg Glover ( talk) 02:21, 2 August 2010 (UTC)
I see a buncha arguments about how pound is defined, as a unit of force or as a unit of mass. I happened to have learned it as a derived unit of force, defined (derived) as the force that accelerates 1 Slug at 1 ft/sec2. All very neat when one first learned the MKS system which has mass (and length and time) as the fundamental units. It is a simple matter of replacing the Kg with the Slug and the meter with the foot. Viola! Simple! That bastard unit, the ugly "pound-mass", is for people who don't really understand. It's also used for a few bad-old engineering traditions - like that awful "Specific Impulse" being expressed in "seconds" by canceling lbf with lbm for crying out loud! - lbf/(lbm/sec) = "seconds"?! (WTF?!). Anyway, lbm is really mostly just an annoyance promulgated by the ignorant, IMHO (big smiley).
But, what really matters is the current way it is defined by the real standards organizations, right? - not how it is explained by some internet engineering toolbox. My question is: "If we write "lb" or "pound" without other clarifying context, does it mean force or mass?" In the whole of my 30 year engineering career, it's meant force and that's how I've made edits. BUT! It could very well actually mean mass IF it is defined that way by the big standards organizations (not by some web page). It could also very well be defined as both, again by the big standards guys. I went with force. If we want to switch it to mass or both, I think we need to cite it well with that really good reference from those big standards orgs.
108.7.241.145 ( talk) 18:38, 14 January 2011 (UTC)
The article name should be "Pound (force)." When the ambiguous term pound is used as a force, it's pronounced "pound", not "pound-force." Gerardw ( talk) 10:25, 12 September 2011 (UTC)
Weight is an ancient word, meaning measure (-t) of something swung (weigh, as in anchors a-weigh = swing, ie rise, the anchor). In common parlance, weight means mass, the expression of which is force. We feel the effects of force and inertia, not of mass. Weight also is used for (statistical) load.
Some parts of science have undertaken to apply gaussian LMT theory to all metrological matters, and their particular use of terminology to match. One sees all sorts of confusion as to what a 'cubic acre' might mean: it means an acre in cube (ie a volume of a cube, the face-area an acre), not an acre-cubed (ie a measure of six dimensions). Less fancifully, one sees that the vary oldest metrics have units of money. Latimer Clarke's 1890 dictionary of scientific units contains plenty of references to this, at the same ratios that were used by Mann Wilberforce's 1864 Linn-based units. This dictionary is a hard-cover work for enduring use, so one is interested to see the ratios were still in force right up to at least the great war.
Another source of endless confusion is where units are used where gaussian LMT theory (quantities have dimensions) clearly do not apply. What actually has dimensions are scales. There is a scale of force from mass (ie force-of-weight), measured in terms of mass itself (just as flux of displacement is measured in terms of the enclosed charge). There is a scale of force by F=ma, where mass and acceleration are measured in the usual units. There is also a scale of mass by this formula.
There are coherent units of mass defined by F=ma, the dimensions of which become 'MT²/L', eg fps slug, inch-pound-second (slinch), cgs (glug), mks (hyl, TME, par or mug). There are coherent units of force by F=ma fps (poundal), cgs (dyne), mks (big-dyne, newton). Some people have suggested different names for mass vs force, eg lbm vs lbf, or gram vs pond. One has even suggested that fors ought be a unit of acceleration (eg 9.80665 m/s²), so lb fors = lb × gravity.
In practice, these theories about foot-slug-second and m-kgf-s being separate systems to foot-pound-second etc, is little more than arrogance in supposing that the LMT theory is correct in all instances, and that these units are free-standing absolute scales in alternation to fps etc. Nothing is further from the truth.
The whole point of using lb vs lbf, and even units like (lb-s²/ft)-mol, is that there exists an equity between mass and force provided by gravity, and that 'lb' is indifferently mass and force (ie weight). As such, one can measure m in lb, create directly a force lb, and then create a 'reactive mass' by lb/celo = lb.s²/ft. The lbf based units are largely meaningless unless it calls down to an lbm, and that there are parallel units related in the ratio of 1:32.175 or ft/s² : gravity.
-- Wendy.krieger ( talk) 07:55, 29 September 2011 (UTC)
-- Wendy.krieger ( talk) 11:12, 30 September 2011 (UTC)
This table could perform a valuable service in helping readers gain traction on how these various units relate. Instead, I found it tremendously confusing because the cells on the col=row diagonal, don't make sense.
According to the row and column headers, these cells should all be occupied by the number '1'. Instead, they are occupied by a specification of the row quantity in terms of mass units (and not according to the force units in the column headers).
That information could indeed be quite useful, but I urge that it be placed in a separate column "Relationship to mass units" or some such. If it is added, please spell out the values of gn so that the relationship is clear.
Of particular significance for this article: 1 lbF, which is here shown as gn * (1 lb) (with only the link to tell us that this is lbM) should also be spelled out as: 32.174 lbM-ft/s^2. Similarly 1 kp = gn 1 kg should be spelled out as 9.8.. kg m/s^2
Hope that this achieves some consensus and can be implemented. Gwideman ( talk) 03:05, 9 July 2014 (UTC)
Traditionally, a pound force was used in engineering, other than in strength of materials or in dynamics, but as per Hooke's Law (F = kx) -- the strength of a spring was listed in the catalog specifications as force per length (expanded or compressed). This is why the official re-definition of pound as limited to a unit of mass for trade purposes is lacking. A spring catalog is of course used for trade. 173.162.253.101 ( talk) 20:35, 11 May 2016 (UTC)
It seems that, often enough, one is supposed to know from context which unit, pound(mass) or pound(force) is meant. Jet engine thrust is commonly in pounds, and obviously enough, not pounds(mass). At a nearby air museum, a jet engine thrust is given in pounds, and converted to kg (oops). They are supposed to be fixing the sign, as there is official (Smithsonian) documentation requesting pounds and newtons. For quantities of matter, pound normally means pound(mass). Gah4 ( talk) 11:45, 9 February 2019 (UTC)
When I read about a rocket, for example Space X's proposed Raptor, producing "380,000 pounds of thrust", Is a "pound of thrust" the same as a pound (force)?
Either way, why is pound of thrust a red link? -- John Maynard Friedman ( talk) 08:20, 1 August 2019 (UTC)
The first paragraph of the article is problematic. In actual practice, the term "pound" and the abbreviation "lb" are used both for "pound mass (lbm)" and "pound force (lbf)." Both are correct. Where the meaning of "lb" isn't clear from context and the habits of the particular technical community, using "lbm" or "lbf" is not a bad idea. What is incorrect is the suggestion that the unqualified unit "pound (lb)" specifically means "lb mass" and not even to mention the qualified abbreviation, "lbm." In the past some authority may have defined it that way but in fact both conventions are popular. 2601:14F:4500:46A0:223:7DFF:FEC4:2D73 ( talk) 04:27, 22 January 2020 (UTC)
The conversions can live in their own entry at the end. The article is about pound-force, from the foot-pound-second system. There are many other articles that need this cleanup too. 38.92.150.242 ( talk) 06:21, 27 March 2024 (UTC)
This
level-5 vital article is rated Start-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||
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It seem interesting to define a quantity that can be directly measured in terms of a quantity that cannot be directly measured and may just be a mathematical convenance.-- 208.54.14.122 ( talk) 08:35, 3 July 2010 (UTC)
PatrickandBrenda 03:10, 11 August 2007 (UTC) In the United States, which is the primary user of the pound-force, the pound-force is almost universal in its application to industry and throughout daily life. I challenge anyone to reasonably argue
"In most daily contexts in the United States, the term “pound” refers unambiguously to a unit of force. Bathroom scales intrinsically display weight or force. An important note, all scales read force as only a balance such as used in a doctor's office can determine mass. A truck carrying one-thousand pounds of wood refers to the weight or force the wood exerts on the truck. At a local grocery store, one pound of meat will refer to the force or weight of the meat, and may even be weighed using a scale at the meat counter..."
I also challenge people who oppose this to present common everyday uses or pound-mass (other than niche industry uses).
The pound force has historically and continues to be today the primary use of the word "pound." As a Senior Mechanical Engineer for Westinghouse Electric Co. (Other employers include Terex Corp. and Emerson Process Management among others) I have never encounter a company (outside steam power plant designers) that ever (used in the literal sense) use pound-mass.
I think a lot of this discussion is missing the point about the pound-f in the system of units. It is entirely true that people have used force and mass interchangeably in the popular setting because a pound of mass produces a pound of force in Earth's gravity where most people experience it. However, there are other units to be considered here. What about the FPS units for energy? -- ft-lbs. Energy must be a distance multiplied by a force, not by a mass. So a pound-mass may be the common and legal/commercial definition, but for the rest of the system to be coherent, lb-f needs to be used. ArkianNWM ( talk) 19:37, 24 April 2009 (UTC)
Will you guys stop this edit warring and find a cite to settle the matter? , revert... It's not like this is a matter of opinion or anything. -- Yath 07:41, 19 August 2007 (UTC)
I don't see reverting patent nonsense as edit warring. You don't have to look very far for a ref--try slug (mass). This statement:
"One pound-force is the force equivalent to that exerted on a mass of one slug accelerated by gravity on the (idealized) surface of Earth or one avoirdupois pound at an acceleration of gravity divided by the universal gravitational constant."
is false. A pound (force) is the amount of force exerted by gravity on a pound (mass). That's why it's called that. The idea that the universal gravitational constant is involved is absurd. The units don't even work out. Rracecarr 15:39, 19 August 2007 (UTC)
The acceleration due to gravity is given to an absurd number of decimal places, given that it varies from place to place. In fact, this article generally uses too many significant digits. Even when your numbers are exact (or of arbitrary precision), it just looks bad.
Also, pound-force is the common unit, not pound-mass. Sure, you can generally get away without making a distinction, which is why some people get confused, but ask any scientist or engineer, and they will tell you that "pound"--unqualified--means pound-force. If you don't believe me, [1] —Preceding unsigned comment added by 141.219.154.178 ( talk) 16:32, 14 November 2007 (UTC)
Someone has changed the GravEngAbs (Three approaches to mass and force units) box in the Foot-pound-second systems of units section. You can even see the error within the link: Grav = Gravitational; Eng = Engineering and Abs = Absolute! It was correct last week (21 JUL 10). Also check the English Engineering Units page it has the correct units of measure. This week the Engineering heading is switch with the Gravitationl heading. The Engineering system is non-coherent: . The Gravitationl system is coherent: .
Can someone fixs this error? I tried and don't know how to access the original box. Greg Glover ( talk) 23:27, 27 July 2010 (UTC)
Whom ever redirected FPS here has made a grave mistake. The pound force is only found in two of the three subsystems. The system is called the Foot-Pound-Second System or FPS.
Worthington from Great Britain ( http://www.archive.org/stream/dynamicsofrotati00wortiala#page/8/mode/2up) gives two of the subsystems as, Gravitational or Engineer’s and Absolute. Obert from the United States gives the three subsystems as Technical, Engineering, and Absolute.
It is clear to me that the Foot-Pound-Second System should have its own page. A disclaimer could be made until someone finds a reference.
Further, I think this is why someone tampered with the GravEngAbs box. The three systems are, if deduced by both Worthington and Obert and applied here at Wikipedia as:
Otherwise:
Greg Glover ( talk) 02:21, 2 August 2010 (UTC)
I see a buncha arguments about how pound is defined, as a unit of force or as a unit of mass. I happened to have learned it as a derived unit of force, defined (derived) as the force that accelerates 1 Slug at 1 ft/sec2. All very neat when one first learned the MKS system which has mass (and length and time) as the fundamental units. It is a simple matter of replacing the Kg with the Slug and the meter with the foot. Viola! Simple! That bastard unit, the ugly "pound-mass", is for people who don't really understand. It's also used for a few bad-old engineering traditions - like that awful "Specific Impulse" being expressed in "seconds" by canceling lbf with lbm for crying out loud! - lbf/(lbm/sec) = "seconds"?! (WTF?!). Anyway, lbm is really mostly just an annoyance promulgated by the ignorant, IMHO (big smiley).
But, what really matters is the current way it is defined by the real standards organizations, right? - not how it is explained by some internet engineering toolbox. My question is: "If we write "lb" or "pound" without other clarifying context, does it mean force or mass?" In the whole of my 30 year engineering career, it's meant force and that's how I've made edits. BUT! It could very well actually mean mass IF it is defined that way by the big standards organizations (not by some web page). It could also very well be defined as both, again by the big standards guys. I went with force. If we want to switch it to mass or both, I think we need to cite it well with that really good reference from those big standards orgs.
108.7.241.145 ( talk) 18:38, 14 January 2011 (UTC)
The article name should be "Pound (force)." When the ambiguous term pound is used as a force, it's pronounced "pound", not "pound-force." Gerardw ( talk) 10:25, 12 September 2011 (UTC)
Weight is an ancient word, meaning measure (-t) of something swung (weigh, as in anchors a-weigh = swing, ie rise, the anchor). In common parlance, weight means mass, the expression of which is force. We feel the effects of force and inertia, not of mass. Weight also is used for (statistical) load.
Some parts of science have undertaken to apply gaussian LMT theory to all metrological matters, and their particular use of terminology to match. One sees all sorts of confusion as to what a 'cubic acre' might mean: it means an acre in cube (ie a volume of a cube, the face-area an acre), not an acre-cubed (ie a measure of six dimensions). Less fancifully, one sees that the vary oldest metrics have units of money. Latimer Clarke's 1890 dictionary of scientific units contains plenty of references to this, at the same ratios that were used by Mann Wilberforce's 1864 Linn-based units. This dictionary is a hard-cover work for enduring use, so one is interested to see the ratios were still in force right up to at least the great war.
Another source of endless confusion is where units are used where gaussian LMT theory (quantities have dimensions) clearly do not apply. What actually has dimensions are scales. There is a scale of force from mass (ie force-of-weight), measured in terms of mass itself (just as flux of displacement is measured in terms of the enclosed charge). There is a scale of force by F=ma, where mass and acceleration are measured in the usual units. There is also a scale of mass by this formula.
There are coherent units of mass defined by F=ma, the dimensions of which become 'MT²/L', eg fps slug, inch-pound-second (slinch), cgs (glug), mks (hyl, TME, par or mug). There are coherent units of force by F=ma fps (poundal), cgs (dyne), mks (big-dyne, newton). Some people have suggested different names for mass vs force, eg lbm vs lbf, or gram vs pond. One has even suggested that fors ought be a unit of acceleration (eg 9.80665 m/s²), so lb fors = lb × gravity.
In practice, these theories about foot-slug-second and m-kgf-s being separate systems to foot-pound-second etc, is little more than arrogance in supposing that the LMT theory is correct in all instances, and that these units are free-standing absolute scales in alternation to fps etc. Nothing is further from the truth.
The whole point of using lb vs lbf, and even units like (lb-s²/ft)-mol, is that there exists an equity between mass and force provided by gravity, and that 'lb' is indifferently mass and force (ie weight). As such, one can measure m in lb, create directly a force lb, and then create a 'reactive mass' by lb/celo = lb.s²/ft. The lbf based units are largely meaningless unless it calls down to an lbm, and that there are parallel units related in the ratio of 1:32.175 or ft/s² : gravity.
-- Wendy.krieger ( talk) 07:55, 29 September 2011 (UTC)
-- Wendy.krieger ( talk) 11:12, 30 September 2011 (UTC)
This table could perform a valuable service in helping readers gain traction on how these various units relate. Instead, I found it tremendously confusing because the cells on the col=row diagonal, don't make sense.
According to the row and column headers, these cells should all be occupied by the number '1'. Instead, they are occupied by a specification of the row quantity in terms of mass units (and not according to the force units in the column headers).
That information could indeed be quite useful, but I urge that it be placed in a separate column "Relationship to mass units" or some such. If it is added, please spell out the values of gn so that the relationship is clear.
Of particular significance for this article: 1 lbF, which is here shown as gn * (1 lb) (with only the link to tell us that this is lbM) should also be spelled out as: 32.174 lbM-ft/s^2. Similarly 1 kp = gn 1 kg should be spelled out as 9.8.. kg m/s^2
Hope that this achieves some consensus and can be implemented. Gwideman ( talk) 03:05, 9 July 2014 (UTC)
Traditionally, a pound force was used in engineering, other than in strength of materials or in dynamics, but as per Hooke's Law (F = kx) -- the strength of a spring was listed in the catalog specifications as force per length (expanded or compressed). This is why the official re-definition of pound as limited to a unit of mass for trade purposes is lacking. A spring catalog is of course used for trade. 173.162.253.101 ( talk) 20:35, 11 May 2016 (UTC)
It seems that, often enough, one is supposed to know from context which unit, pound(mass) or pound(force) is meant. Jet engine thrust is commonly in pounds, and obviously enough, not pounds(mass). At a nearby air museum, a jet engine thrust is given in pounds, and converted to kg (oops). They are supposed to be fixing the sign, as there is official (Smithsonian) documentation requesting pounds and newtons. For quantities of matter, pound normally means pound(mass). Gah4 ( talk) 11:45, 9 February 2019 (UTC)
When I read about a rocket, for example Space X's proposed Raptor, producing "380,000 pounds of thrust", Is a "pound of thrust" the same as a pound (force)?
Either way, why is pound of thrust a red link? -- John Maynard Friedman ( talk) 08:20, 1 August 2019 (UTC)
The first paragraph of the article is problematic. In actual practice, the term "pound" and the abbreviation "lb" are used both for "pound mass (lbm)" and "pound force (lbf)." Both are correct. Where the meaning of "lb" isn't clear from context and the habits of the particular technical community, using "lbm" or "lbf" is not a bad idea. What is incorrect is the suggestion that the unqualified unit "pound (lb)" specifically means "lb mass" and not even to mention the qualified abbreviation, "lbm." In the past some authority may have defined it that way but in fact both conventions are popular. 2601:14F:4500:46A0:223:7DFF:FEC4:2D73 ( talk) 04:27, 22 January 2020 (UTC)
The conversions can live in their own entry at the end. The article is about pound-force, from the foot-pound-second system. There are many other articles that need this cleanup too. 38.92.150.242 ( talk) 06:21, 27 March 2024 (UTC)