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Space Forum / Astronomy / September 2004Silly question
This question just come on the radio: "What would a person that weighs 100 pounds weigh on mars" LJ > This question just come on the radio: > > "What would a person that weighs 100 pounds weigh on mars" > > LJ Doing a Google on Mars and Gravity, I see that Mars has about 1/3 the gravity of Earth, so a person weighing 100 pounds on Earth would weigh about 33 pounds on mars. > > This question just come on the radio: > > [quoted text clipped - 5 lines] > the gravity of Earth, so a person weighing 100 pounds on Earth > would weigh about 33 pounds on mars. Isn't 100 pounds a mass? Masses dont change when you take em to mars right? ... The force on which the mass is pulled down in Newton would be less ofcourse. So if someone on earth has a mass of 100 pounds and "g" is 9.8 he's pulled down by 980 Newton. This would be less on mars cause it's constant "g" would be less. >> > This question just come on the radio: >> > [quoted text clipped - 11 lines] >he's pulled down by 980 Newton. This would be less on mars cause it's >constant "g" would be less. pounds are weight. slugs are mass (in english units) kilograms are weight. newtons are mass (in mks) F=MA lbs= slugs*ft/sec^2 kgs= newtons*m/sec^2 slugs are so useless, i'm digging deep into the memory banks to come up with the weight equivalent. ummm. 32 pounds at earth gravity. to the following posters, yeah, mars gravity is about 1/3 earth's. 33 pounds on mars. plus or minus. > pounds are weight. slugs are mass (in english units) Not quite. Pounds are either mass or force. Slugs are always mass and poundals are always force. > kilograms are weight. newtons are mass (in mks) But what do you mean by "weight"? People love to argue about this, but the term weight is imprecise. It is used to refer to either force or mass. It's a trick question. If you think of weight as downward force due to gravity, then a 100 pound Earth person would weigh less on Mars. If you think of it as mass, then a 100 pound Earth person still "weighs" 100 pounds on Mars.  SignatureSteve Gray sgray2@cfl.rr.com w=mg...nothing to argue. F=W=ma and a=gravity. BP >> pounds are weight. slugs are mass (in english units) > [quoted text clipped - 9 lines] > If you think of it as mass, then a 100 pound Earth person still "weighs" > 100 pounds on Mars. > w=mg...nothing to argue. F=W=ma and a=gravity. If you accept those equations then you're right, there's nothing to argue. You've explicitly defined weight (w) as a force. Not everyone accepts that as an appropriate definition. In commerce you constantly hear people referring to merchandise as "weighing" so many kilograms, yet we know that the kilogram is explicitly mass. For what it's worth, I've always agreed with you- weight should be force- but I don't expect it go unchallenged. Physicists refer to force and mass and avoid the whole semantic issue. SignatureSteve Gray sgray2@cfl.rr.com Right Steve, but there is a big difference between what is standardly said in colloquial language and what is meant in science. Of course people measure things in kilos understand that from our stand point that our notion of what a kilo is on earth is OUR notion of mass. Scales are adjusted to compensate for g. This is not about weight or mass, it is about semantics. BP >> w=mg...nothing to argue. F=W=ma and a=gravity. > [quoted text clipped - 7 lines] > but I don't expect it go unchallenged. Physicists refer to force and > mass and avoid the whole semantic issue. >Right Steve, but there is a big difference between what is standardly said >in colloquial language and what is meant in science. Of course people >measure things in kilos understand that from our stand point that our notion >of what a kilo is on earth is OUR notion of mass. Scales are adjusted to >compensate for g. This is not about weight or mass, it is about semantics. You finally got one thing right--the only science involved here is indeed semantics. Gene Nygaard Time flies like an arrow; fruit flies like a banana. > If you accept those equations then you're right, there's nothing to > argue. You've explicitly defined weight (w) as a force. Not everyone > accepts that as an appropriate definition. What is the appropriate definition then Steve? In commerce you constantly > hear people referring to merchandise as "weighing" so many kilograms, yet > we know that the kilogram is explicitly mass. Sure, really ask yourself does the kid at the grocery store interest himself on whether the bananas should be weighed in kg (incorrectly of course) or pounds??? No, commerce does not care about that. Weighing things is bad, because you are accepting the fact that gravity is constant. The G is constant, but g depends on radius. Mass does not change (except when travelling at great speeds), but weight does. The fact is commerce does not bother with little things like that, because they don't need to. > For what it's worth, I've always agreed with you- weight should be force- > but I don't expect it go unchallenged. Physicists refer to force and > mass and avoid the whole semantic issue. See, we agree. BP (Physics grad student) >> If you accept those equations then you're right, there's nothing to >> argue. You've explicitly defined weight (w) as a force. Not everyone >> accepts that as an appropriate definition. > > What is the appropriate definition then Steve? Good question. My point was that people don't agree on an appropriate definition. Physicists define mass and force, but they don't define weight, so people argue about it. > In commerce you constantly >> hear people referring to merchandise as "weighing" so many kilograms, [quoted text clipped - 15 lines] > > See, we agree. Yes. Again, my point was that many people don't. SignatureSteve Gray sgray2@cfl.rr.com Steve, > Good question. My point was that people don't agree on an appropriate > definition. Physicists define mass and force, but they don't define > weight, so people argue about it. Actually, weight is defined as W=mg by physicists. The fact that others use creative interpretations is really what we are talking about. In the Handbook of Physics it defines weight in such a manner. "Weight, the attractive force (gravitation) of Earth that affects all bodies. It is proportional to the mass of the body. The proportionality constant is the acceleration of the gravity g that , at a given point, is identical for all bodies independent of their mass." Now here is the meat of the matter, this starts to become like a social argument. Science is not an adaptable discipline. It is. Unlike language which changes over time, science is changed when a consensus is made and only when certain criteria are satisfied (published findings, reproducable results...etc.). My example for language was one of the aristocracy in Great Britain calling the Tower of London "Aweful." She meant literally full of awe. > Yes. Again, my point was that many people don't. That is okay too. But we know better. We need to educate those who don't...but want to know. Such discussion are vital to understanding science. BP >Steve, > [quoted text clipped - 4 lines] >Actually, weight is defined as W=mg by physicists. The fact that others use >creative interpretations is really what we are talking about. What's this nonsense about "creative interpretations"? Can you show me by what authority any physicist was ever given any say-so in what the word "weight" means on my bottle of ketchup, "Net wt. 24 oz (1 lb 8 oz) 680 g"? There is no creative interpretation in the usage of the word "weight" in commerce--something which, by the way, is much more consistent and uniform than the usage of the word "weight" in science. Witness this: "molecular weight" 1,050,000 hits "molecular weight" site:nist.gov 2,860 hits The word weight entered the English language over 1000 years ago, meaning the quantity measured with a balance. That quantity is MASS, not force. At that time, these measurements were used only for the purpose of determining how much stuff people had, for the purpose of trade. We still measure the very same word, with the very same meaning, for the very same purposes, today in the 21st century. The only science involved here is semantics, a branch of linguistics. This usage is also quite proper and correct in history and in the law. Where in the world would you imagine any error in this process--or any "creative interpretation" as you put it? I think you are confused about who is using creative interpretations. The original and still-common meaning is quite straightforward. Do you imagine it to be an error that those heathen tribesmen in what is now the U.K. were unable to discern the God-given word they were supposed to invent for this purpose? SignatureGene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ "It's not the things you don't know what gets you into trouble. "It's the things you do know that just ain't so." Will Rogers > Can you show me by what authority any physicist was ever given any > say-so in what the word "weight" means on my bottle of ketchup, "Net > wt. 24 oz (1 lb 8 oz) 680 g"? The same friggin idiot that uses it incorrectly. It is used incorrectly. Get it or are you that hard headed. Is that same Net wt of 24 oz the same in Denver as it is in Death Valley. No it is not, you idiot. Gravity is different at those point. > Will Rogers BTW quoting Will Rodgers and Groucho Marx does not get you point in the science community. BP [Gene Nygaard wrote] > > Can you show me by what authority any physicist was ever given any > > say-so in what the word "weight" means on my bottle of ketchup, "Net [quoted text clipped - 4 lines] > in Denver as it is in Death Valley. No it is not, you idiot. Gravity is > different at those point. The ketchup certainly does have the same "weight" -- i.e. mass -- in Denver as in Death Valley (assuming for the sake of argument that the variation from one bottle to the next is negligible in comparison to the gravitational difference), because the standards set out for commerce require that scales (and industrial dispensing equipment, I presume) be calibrated to standard masses. You don't see a table or graph of "weight" _vs_ altitude and latitude on labels! You get what it says, wherever you are: in principle it should be the same quantity whether sold at the bottom of a mine or on the moon, and "weight" in the physicist's sense of m*g is a property for which that isn't true. SignatureOdysseus > The ketchup certainly does have the same "weight" -- i.e. mass -- in > Denver as in Death Valley (assuming for the sake of argument that the > variation from one bottle to the next is negligible in comparison to > the gravitational difference), because the standards set out for > commerce require that scales (and industrial dispensing equipment, I > presume) be calibrated to standard masses. O, For the size of the ketchup bottle, the difference is small. But what about large scales. This is really getting away from the point. He picked that honestly as an arbitrary example. And it is a valid example. You don't see a table or > graph of "weight" _vs_ altitude and latitude on labels! You get what > it says, wherever you are: in principle it should be the same > quantity whether sold at the bottom of a mine or on the moon, and > "weight" in the physicist's sense of m*g is a property for which that > isn't true. No, the mass is constant where ever you are at (within certain velocities much less than light). Weight is a force. That changes wrt to the r^2. Yes, on that scale within the realm of commerce/engineering it is a valid example. But it is hardly equal. For people that don't care much it can be called as good as equivalent. F=ma W=F=ma=mg and F=GMm/r^2 The mass changes wrt to the square of the radius. > > The ketchup certainly does have the same "weight" -- i.e. mass -- in > > Denver as in Death Valley (assuming for the sake of argument that the [quoted text clipped - 17 lines] > No, the mass is constant where ever you are at (within certain velocities > much less than light). Weight is a force. That changes wrt to the r^2. Which is why the stated "weight" of packaged goods in fact refers to their mass. > Yes, on that scale within the realm of commerce/engineering it is a valid > example. But it is hardly equal. For people that don't care much it can be > called as good as equivalent. So everyone should use physics jargon at all times, and abandon usages of centuries' standing where they don't conform to technical conventions? > F=ma > W=F=ma=mg This is news? > and F=GMm/r^2 > > The mass changes wrt to the square of the radius. What on earth does that mean? The mass of a sphere is proportional to the *cube* of its radius, but that's not the same r as in this formula, where it stands for the distance between two point masses, with their gravitational attraction being *inversely* proportional to their separation -- hence the expression "inverse-square law". At any rate, if you want to get into technicalities, the above gravitational equation is a gross oversimplification for measuring the acceleration experienced by an object near the Earth's surface. As you approach any extended, inhomogeneous or aspherical body, the approximation of taking its mass to be concentrated at its centroid becomes less and less valid. Not only is the earth neither homogeneous nor spherical, but its rotation causes the apparent weight of an object at a given location to be reduced in proportion to the cosine of its latitude, over and above the effects of oblateness, altitude, local density variations, tides, &c. SignatureOdysseus >> The mass changes wrt to the square of the radius. > > What on earth does that mean? O, Right...Sorry misquoted the inverse square rule. > At any rate, if you want to get into technicalities, ... True, but your point further enhances my original point that using weight to EQUATE a mass is actually apples and oranges. I am not arguing the mechanics of it. That is all plain to see...simplified or full form...point mass or irregular shape without symmetry. But, going back to your size relationship...to that Ketchup bottle the earth looks pretty damn round. I understand, but now this is splitting hairs. BP > At any rate, if you want to get into technicalities, ... > >True, but your point further enhances my original point that using weight to >EQUATE a mass is actually apples and oranges. I am not arguing the Pronghorns and antelope is a more apt analogy. Or bison and buffaloes. Tangerines and oranges are different things; but a Mandarin orange is a tangerine. Get it through your head that we who use this word "weight" in commerce own this word. We have a prior claim to it by around 800 years over the physicists who only borrowed it about 275 years ago and often use it with a different meaning. You have no standing to complain about our usage. There never was any "equating" of weight with mass, since mass did not have this meaning until the 18th century either, many centuries after the word weight was coined with this meaning, the quantity measured with a balance. >mechanics of it. That is all plain to see...simplified or full form...point >mass or irregular shape without symmetry. But, going back to your size >relationship...to that Ketchup bottle the earth looks pretty damn round. I >understand, but now this is splitting hairs. But it doesn't look so round to a 401.23 troy ounce bar of platinum. The principle is the same. The method of testing and calibrating scales is exactly the same for the sale of ketchup as it is for the sale of platinum. Newtons are not legal units for the sale of goods anywhere in the world. Kilograms force are not legal units for the sale of goods anywhere in the world. Pounds force are not legal units for the sale of goods anywhere in the world. And there are no carats force, and there are no troy ounces force. Gene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/t_jeff.htm But if it be thought that, either now, or at any future time, the citizens of the United States may be induced to undertake a thorough reformation of their whole system of measures, weights and coins, reducing every branch to the same decimal ratio already established in their coins, and thus bringing the calculation of the principal affairs of life within the arithmetic of every man who can multiply and divide plain numbers, greater changes will be necessary. U.S. Secretary of State Thomas Jefferson, 1790 > Get it through your head that we who use this word "weight" in > commerce own this word. Not arguing that, no matter how wrong it is...you still use it. We have a prior claim to it by around 800 > years over the physicists who only borrowed it about 275 years ago and > often use it with a different meaning. Stay in the 1200's then while I learn today's physics. > You have no standing to complain about our usage. No, I just began this by saying that it was mixing a.shole and jerks. > There never was any "equating" of weight with mass, since mass did not > have this meaning until the 18th century either, Not true, people had ideas before hand. It just never got the attention. Or did you think Newton just made all of it up himself? > Newtons are not legal units for the sale of goods anywhere in the > world. Kilograms force are not legal units for the sale of goods > anywhere in the world. Pounds force are not legal units for the sale > of goods anywhere in the world. And there are no carats force, and > there are no troy ounces force. I never said any of this had validity, that came out of your a.s. Newtons for commerce is just as silly as pounds. Kilos are prefered in my book, jackass. This is because you can sell a kg of a.shole ( 1/1000 of a Gene) and it would still be a kg on earth...and you won't have to do all of that calculating gravity sh.t. BP "Keep It Simple, Stupid" -? >> Get it through your head that we who use this word "weight" in >> commerce own this word. [quoted text clipped - 28 lines] >and it would still be a kg on earth...and you won't have to do all of that >calculating gravity sh.t. You don't have to do any "calculatinig gravity sh.t" when you sell goods in pounds either. They are defined as 0.45359237 kg. There is absolutely no difference in the use of kilograms and pounds in this regard, other than the size of the units. One would think that by the time someone becomes a graduate student, he would have some ability to comprehend what he reads. So since you are go goddamn slow, I'll give you a third chance to read the official definition of a pound: http://www.ngs.noaa.gov/PUBS_LIB/FedRegister/FRdoc59-5442.pdf Announcement. Effective July 1, 1959, all calibrations in the U.S. customary system of weights and measures carried out by the National Bureau of Standards will continue to be based upon metric measurement standards and, except those for the U.S. Coast and Geodetic Survey as noted below, will be made in terms of the following exact equivalents and appropriate multiples and submultiples: 1 yard= 0.914 4 meter 1 pound (avoirdupois)= 0.453 592 37 kilogram Currently, the units defined by these same equivalents, which have been designated as the International Yard and the International Pound, respectively, will be used by the National Standards Laboratories of Australia, Canada, New Zealand, South Africa, and United Kingdom; thus there will be brought about international accord on the yard and pound by the English-speaking nations of the world, in precise measurements involving these basic units. You only need to do "calculating gravity sh.t" if you use pounds force. Funny thing is, there is no "official" definition of a pound force. There is no official value to use in this "calculating." There is for kilograms force; it is the value which is used to define kilograms force which is often borrowed to define pounds force as well, but other values such as 32.16 ft/s^2 and 386 in/s^2 are used for this purpose as well. Gene Nygaard See Gene, you still have not learned manners. I guess you have been raised by Scandinavian timber wolves. I know, it's hard being the master race. But, really, I can't play anymore. I've got a test today and some Partial Diff EQ homework. So, until then my friend...blow it out your a.s. >> Get it through your head that we who use this word "weight" in >> commerce own this word. [quoted text clipped - 32 lines] > > "Keep It Simple, Stupid" -? > >> The mass changes wrt to the square of the radius. > > [quoted text clipped - 11 lines] > relationship...to that Ketchup bottle the earth looks pretty damn round. I > understand, but now this is splitting hairs. Excuse me, wasn't it you who said that anyone who would describe the mass of something as "net wt." must be a "friggin idiot"? To the 'man on the street' the physicist's distinction between mass and weight -- like this entire subthread -- is itself a matter of "splitting hairs". And that you seem to have some difficulty with the concept yourself, or at least in choosing the 'correct' word of the two, makes me wonder why you find a 'loose' or potentially ambiguous non-technical usage of "weight" so objectionable, especially in a context where the meaning should be obvious. In any physics paper or textbook the dimensions used in the equations should remove any doubt there may be as to exactly what is meant by "weight", "pounds", &c. in the text. But I doubt theoretical physicists have much occasion to use either term these days. SignatureOdysseus > Excuse me, wasn't it you who said that anyone who would describe the > mass of something as "net wt." must be a "friggin idiot"? Yeah, I was being a dick to a jerk...so what? I was ungentlemanly and rude to a jerk that was calling me an idiot. So...is there a problem with that? Where I grew up in Chicago, those were fighting word. Anyone can hide behind a computer and call someone an idiot, even me. There is no accountability for it. If you want to have a gentlemanly discussion. Sure. We can always agree to disagree on matter. Seems you two can't do that. If you want to call me an idiot, like this jerk did then we can take it outside. It's kind of like applying Newton's third to a.sholes. To the 'man > on the street' the physicist's distinction between mass and weight -- > like this entire subthread -- is itself a matter of "splitting > hairs". I said that it was an incorrect use of the term. It is incorrect as far as i am concerned. You want to argue about "technically...so and so" then we can go on forever "splitting hairs" because of all the assumptions made in physics. Mixing weight and mass is stupid. One takes into account acceleration and one doesn't. We can drop the gauntlets forget about symmetry and linearity and really go for it. Round three...non linear systems in dynamics or even n-body problems. And that you seem to have some difficulty with the concept > yourself, or at least in choosing the 'correct' word of the two, > makes me wonder why you find a 'loose' or potentially ambiguous > non-technical usage of "weight" so objectionable, especially in a > context where the meaning should be obvious. Not, at all. I have a decent grasp of mechanics for physics. I just can't write very well. I speak 3 languages and am learning a fourth: Ukrainian was first, English was second aber als dritten spreche ich fast fliessent Deutsch und nehongo-gah wakahdimas (can understand a little Japanese) . As a result often my verbage is not correct or I don't get it out. Honestly, I need an editor for my editor. So, I switched mass and force. That is something I acknowledge (which takes a lot for a physics major). I am man enough to do that. I said that I miss quoted force. But, its not so funny as to how some of you have a huge ax to grind. The reason I find it not good is exactly the same reason why I have to explain this to you and the a.shole. In the German language things are very 'precise'. I learned many times that even the use of certain words in certain context can land you in deep trouble. Similarly, physics is a science that thrives on precision and accuracy. You guys keep doing all your handwaving and I will keep saying what I say. I choose to remove all of the vagueness, while you two can go on rehashing this argument of weight mass pounds and kilos. There are better topics to discuss. It's funny you and Gene just want to argue for the sake of argument. I get a kick out of it, especially when Gene talks to the audience (I can that too, eh Nygaard.) and calls me names. Most of the people get turned off by that so the don't bother jumping in to the conversation. What you don't realize is that no matter what I am sold on my arguement. You can yell and insult all you want, but papers, solid support, and repeatable experiments is what changes my mind. Until then I am a skeptics skeptic. Have Gene try and publish his website in a journal. If anything. If I remember correctly there was one on measures and standards, but the name escapes me. It seems more like a historical arguement instead of a scientific one. It's not just about theoretical physicists...which I am not. My chosen discipline is Computational Astrophysics. The computer is a great tool to augment astronomy and is very relevant in other fields. So, while I am still learning about a lot of the intricacies of celestial mechanics and hydrodynamics...I think I may have a decent grasp of it. At least my profs have passed me, well. > In any physics paper or textbook the dimensions used in the equations > should remove any doubt there may be as to exactly what is meant by > "weight", "pounds", &c. in the text. But I doubt theoretical > physicists have much occasion to use either term these days. Right only a few that I have seen still mention pounds as mass, incorrectly, and they were Russian. Right, we kind of stick with mass because is it more fundamental. BP >The reason I find it not good is exactly the same reason why I have to >explain this to you and the a.shole. In the German language things are very [quoted text clipped - 4 lines] >of the vagueness, while you two can go on rehashing this argument of weight >mass pounds and kilos. There are better topics to discuss. Google: "molecular weight" site:.de 65 700 hits Molekulargewicht site:.de 12 900 hits The word "Gewicht" is just as ambiguous in German as "weight" is in English. This "Gewicht" is no more a force than its English counterpart. But it didn't have to be that way. This is a language-specific problem, one shared by English by some other languages such as German. But there are other languages in which the physicists did not make such a silly choice when choosing a jargon word for the force due to gravity. For example, in the Norwegian language the term "vekt" (vikt, wægt, etc. in earlier spellings) was not chosen for this purpose. Instead, physicists use the word "tyngde." So what it boils down to is an idiotic choice of a jargon word. Funny thing is, it wasn't even the physicists who made this choice in English. It was made for them by an otherwise obscure translator named Andrew Motte, translating Newton's major work into English after Newton's death. We aren't in the market for a new word to use in commerce. So if the ambiguities bother you, guess who should be out shopping for a new word! Gene Nygaard I was not arguing how the Germans us it butt muncher. BP >>The reason I find it not good is exactly the same reason why I have to >>explain this to you and the a.shole. In the German language things are [quoted text clipped - 37 lines] > > Gene Nygaard >> Can you show me by what authority any physicist was ever given any >> say-so in what the word "weight" means on my bottle of ketchup, "Net [quoted text clipped - 4 lines] >in Denver as it is in Death Valley. No it is not, you idiot. Gravity is >different at those point. Of course that net weight is the same in Denver as it is in Death Valley. Or at the North Pole. Or atop Mt. Chimborazo. As it should be. What more do you need? Maybe you should learn to evaluate the credibility of your sources better. Like I said, Chicolini, it takes a real damned fool to insist that when we buy and sell goods by weight, we'd want to measure some quantity that varies with location. Weight is NEVER a force when anybody talks about "net weight" of anything, nor of "tare weight" of its container. "Net weight" is not a physics term; if you are interested in weight in one of its force definitions, then the container is not invisible to gravity. The force due to the container is indistinguishable from the force due to the contents. Weight is also NEVER A FORCE when anybody talks about "atomic weight" or" molecular weight" or "formula weight." So get over the idea of a uniform, consistent usage of this word in science and engineering. Weight is never a force when anybody talks about "carat weight" of a diamond. Weight is never a force when anybody talks about "troy weight" of precious metals or opals. Weight is not a force in normal rocket scientist usage, when they talk about "thrust-to-weight ratios." Now, with regard to the original "Silly Question"in this thread--weight is not a force in the medical sciences or in sports when we talk about body weight--and those are the normal reasons we weigh ourselves. Our weight would not change on the moon, in the normal and proper usage of medicine and sports. The kilograms used for this purpose throughout the world, including many if not most hospitals in the United States, are the proper SI units for this purpose. As you know, while kilograms force exist, they are not a part of SI and are never the proper SI units for anything. The same is true, of course, for the body weight of other animals as well as humans in zoology, or in paleontology. Weight is not a force in the name of the National Conference on Weights and Measures, nor in the English names of the BIPM (International Bureau of Weights and Measures), the CGPM (General Conference on Weights and Measures), and the CIPM (International Committee for Weights and Measures). Weight is not a force when we talk about "shipping weight." Weight is not a force when we talk about "curb weight" or "kerb weight" of a vehicle. Weight is not a force when we talk about "carcass weight" ("carcase weight") of butchered livestock. Weight is not a force when we talk about "basis weight" of paper. Gene Nygaard "Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." - Albert Einstein > What more do you need? Maybe you should learn to evaluate the > credibility of your sources better. Maybe, you should understand that disagreeing can be done in a gentlemanly manner. Not by name calling. Really, all I want to do is bug you...not listen to any of your points. Even if some may be valid. And, what is your credibility. Someone that lays claim for the all those oppressed nonphysicists to fight the fascist physicists. Most of the ideas you have brought up were not argued by me nor said by me. > Like I said, Chicolini, it takes a real damned fool to insist that > when we buy and sell goods by weight, we'd want to measure some > quantity that varies with location. Hey kleine arschloch, I never said anything about using weight to by and sell. That was your mistake. But, you are not man enough to admit that. I was trying to make the same point that it would be stupid to use weight. See you are really just arguing yourself. I said it was better to use mass. There are the same everywhere and you don't have to do all the calculations adjusting for gravity...etc. > Weight is also NEVER A FORCE when anybody talks about "atomic weight" Atomic weight is another outdated term, monkey spanker...They refer to Relative Atomic Mass now, chum muncher. > Now, with regard to the original "Silly Question"in this > thread--weight is not a force in the medical sciences or in sports > when we talk about body weight--and those are the normal reasons we > weigh ourselves. Our weight would not change on the moon, in the > normal and proper usage of medicine and sports. Nothing was ever said that specific, shmuck. How can you avoid gravity, dingbat? Is your scale properly calibrated to any international standard, ayatollah of a.s-ahole-a? And can you take that same scale and reproduce the experiment of weighing your self on the same device on another planet??? Aha, but your mass remains the same big lump of a.shole for eternity...no matter where you are. The kilograms used > for this purpose throughout the world, including many if not most > hospitals in the United States, are the proper SI units for this > purpose. Smarter to use. BP >> Weight is also NEVER A FORCE when anybody talks about "atomic weight" > >Atomic weight is another outdated term, monkey spanker...They refer to >Relative Atomic Mass now, chum muncher. Oh, get real! Go look at some of the zillions of periodic tables on the Internet, many of them from colleges and universities all around the world, which use "atomic weight." I've already told you about molecular weight earlier in this thread: >>Google >> "molecular weight" 1,050,000 hits >> "molecular weight" site:nist.gov 2,860 hits You can check various other things as well: "atomic weight" 117,000 hits "atomic wt" 789 hits "molecular weight" site:harvard.edu 5060 hits "molecular weight" site:.uk 42 800 hits "molecular weight" site:.au 11 400 hits Gene Nygaard Sorry, most of them are switching to relative atomic mass. chum muncher. They may have it on the sites but it is becoming the standard. monkey spanker dim wit. BP >>> Weight is also NEVER A FORCE when anybody talks about "atomic weight" >> [quoted text clipped - 19 lines] > > Gene Nygaard >> If you accept those equations then you're right, there's nothing to >> argue. You've explicitly defined weight (w) as a force. Not everyone [quoted text clipped - 9 lines] >on whether the bananas should be weighed in kg (incorrectly of course) or >pounds??? As Steven and I have already pointed out, those pounds are legally defined as units of mass, exactly equal to 0.45359237 kg. There can be no difference between the propriety of using kilograms and the propriety of using pounds, other than the fact that kilograms are part of the interdisciplinary and International System of Units. Both units are units of mass. Why in the world do you suppose the law bothers defining pounds in the first place? The real question you need to look at is not the "kid at the grocery store." You need to look at what the manufacturers measure in putting labels on their products, and you need to especially look at what government inspectors do when they test and certify the scales made in commerce, or measurements made with those scales. That process is well established and uniform, worldwide--something that has been going on for thousands and thousands of years (this government regulation was already old hat when Hammurabi included such provisions in his Code of Laws 3750 years ago). > No, commerce does not care about that. Weighing things is bad, >because you are accepting the fact that gravity is constant. It isn't constant. Even if you limit yourself to sea level on Earth, it varies by more than one part in 190. Throw in Mt. Chimborazo, the highest mountain on Earth, and the variation is more than 0.72% Do you suppose that might make a difference in the troy weight of a 401.23 oz bar of platinum, if anybody were damn fool enough to ever have used units of force for this purpose rather than units of mass? Note that this is one significant difference between the troy units of weight and their avoirdupois cousins, and between the troy units and grams and kilograms as well--the troy units have never spawned units of force of the same name. Troy ounces are always units of mass, and always have been. In fact, pounds force are such a recent bastardization that they are uniquely identified by that name. Of all the hundreds of different pounds used at various times and places throughout history, only one of them has spun off a unit of force of the same name. The others were all units of mass, including those "metric pounds" of 500 grams still used informally in many parts of Europe and Latin America, a 19th century redefinition replacing many different older pounds. SignatureGene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ "It's not the things you don't know what gets you into trouble. "It's the things you do know that just ain't so." Will Rogers Gene, You are wrong. I polled most of the physics professors at my university, they say you are the idiot. BP >>> If you accept those equations then you're right, there's nothing to >>> argue. You've explicitly defined weight (w) as a force. Not everyone [quoted text clipped - 55 lines] > still used informally in many parts of Europe and Latin America, a > 19th century redefinition replacing many different older pounds. >>> > This question just come on the radio: >>> > [quoted text clipped - 13 lines] > >pounds are weight. slugs are mass (in english units) True >kilograms are weight. newtons are mass (in mks) Backwards >F=MA > >lbs= slugs*ft/sec^2 > >kgs= newtons*m/sec^2 Also backwards >slugs are so useless, i'm digging deep into the memory banks to come >up with the weight equivalent. ummm. 32 pounds at earth gravity. > >to the following posters, yeah, mars gravity is about 1/3 earth's. > >33 pounds on mars. plus or minus. <<Remove the del for email>> > >>> > This question just come on the radio: > >>> > [quoted text clipped - 36 lines] > > <<Remove the del for email>> Where is Donald Shead when we need him! Double-A >>pounds are weight. slugs are mass (in english units) > [quoted text clipped - 20 lines] > ><<Remove the del for email>> <major cringe> there i go again. making an a.s of myself. in my defense, i knew "slugs" were the units of english-measure mass, i had assumed that the far less used "newton" was the metric alter ego. apply F=MA, and well, here i am. thanks folks. i consider myself "educated." > there i go again. making an a.s of myself. > [quoted text clipped - 3 lines] > > thanks folks. i consider myself "educated." Careful, saying that... BP I was waiting for someone to say that, but yes pounds are force and slugs are mass. Source "An Introduction to Mechanics", Kleppner and Kolenkow, p.65. However... sorry, kilograms are mass and Newtons are force. N=km*m/sec^2 "The kilogram is the mass of an international prototype of the kilogram. It is a Pt-Ir cylinder deposited at the BIPM in Severs, near Paris." Source "Handbook of Physics" Bennison, Harris, Stocker, Lutz, page 1125. Meter, Kilograms, Second refers to Length, Mass, and Time. You are XX kilograms no matter where you are in the galaxy. BP > pounds are weight. slugs are mass (in english units) > kilograms are weight. newtons are mass (in mks) [quoted text clipped - 11 lines] > > 33 pounds on mars. plus or minus. >I was waiting for someone to say that, but yes pounds are force and slugs >are mass. Go study this until you understand it-- http://w0rli.home.att.net/youare.swf Pounds are and always have been units of mass. Since 1959, they have been defined, worldwide, as units of mass exactly equal to 0.45359237 kg. Here is the current official definition of the pound in the U.S., the same as the definition in the rest of the world. See the document itself for a discussion of the prior U.S. definition since 1893, as a slightly different exact fraction of a kilogram. http://www.ngs.noaa.gov/PUBS_LIB/FedRegister/FRdoc59-5442.pdf Announcement. Effective July 1, 1959, all calibrations in the U.S. customary system of weights and measures carried out by the National Bureau of Standards will continue to be based upon metric measurement standards and, except those for the U.S. Coast and Geodetic Survey as noted below, will be made in terms of the following exact equivalents and appropriate multiples and submultiples: 1 yard= 0.914 4 meter 1 pound (avoirdupois)= 0.453 592 37 kilogram Currently, the units defined by these same equivalents, which have been designated as the International Yard and the International Pound, respectively, will be used by the National Standards Laboratories of Australia, Canada, New Zealand, South Africa, and United Kingdom; thus there will be brought about international accord on the yard and pound by the English-speaking nations of the world, in precise measurements involving these basic units. Yes, there are also pounds force. They are a recent bastardization, a unit never well defined before the 20th century--and quite surprisingly, a unit which even today doesn't have an "official" definition. They should always be identified as such, and also be distinguished by using a different symbol: American Society for Testing and Materials, Standard for Metric Practice, E 380-79, ASTM 1979. 3.4.1.4 The use of the same name for units of force and mass causes confusion. When the non-SI units are used, a distinction should be made between force and mass, for example, lbf to denote force in gravimetric engineering units and lb for mass. >Source "An Introduction to Mechanics", Kleppner and Kolenkow, p.65. > >However... sorry, kilograms are mass and Newtons are force. There are, of course, also kilograms force. The only difference is that the metric system is still fully supported and updated--and the keepers of our standards have been telling us for over 40 years to stop using kilograms force. Yet we still see many vestiges of the use of those once-but-no-longer acceptable kilograms force. They are used for things such as thrust of rockets and jet engines (do a Google search, or see for example Tom Clancy's nonfiction Airborne, 1997). Those were the normal units for thrust in the Russian space program until at least the late 1980s. We also see things like my torque wrench in "meter kilograms"--I've had it quite a while, but they are still readily available. We see pressure gauges in "kg/cm^2" and even in the United States, tension of bicycle spokes is measured in kilograms force. Note that none of those above-mentioned uses of kilograms force are for anything that is called "weight" in anybody's book. When kilograms are used for something that is called "weight" they are almost always the proper SI units for the purpose. (Of course, as mentioned above, there are no kilograms force in SI, so kilograms force are never the proper SI units for anything.) SignatureGene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ "It's not the things you don't know what gets you into trouble. "It's the things you do know that just ain't so." Will Rogers Your link did not work.. This is from the BIPM website discussing kg as mass... Taking into account the decision of the Comité International des Poids et Mesures of 15 October 1887, according to which the kilogram has been defined as unit of mass; (Note no mention of the word force) Taking into account the decision contained in the sanction of the prototypes of the Metric System, unanimously accepted by the Conférence Générale des Poids et Mesures on 26 September 1889; Considering the necessity to put an end to the ambiguity which in current practice still exists on the meaning of the word weight, used sometimes for mass, sometimes for mechanical force; (Hoorrahhh, somebody with clarity) The Conference declares 1.. The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram; 2.. The word "weight" denotes a quantity of the same nature as a "force": the weight of a body is the product of its mass and the acceleration due to gravity; in particular, the standard weight of a body is the product of its mass and the standard acceleration due to gravity; 3.. The value adopted in the International Service of Weights and Measures for the standard acceleration due to gravity is 980.665 cm/s2, value already stated in the laws of some countries. > Go study this until you understand it-- > http://w0rli.home.att.net/youare.swf Provide a proper link, so I can educate myself. I understand your arguements...but they are all instances of what you refer to as "bastardization". > Pounds are and always have been units of mass. Since 1959, they have > been defined, worldwide, as units of mass exactly equal to 0.45359237 > kg. Sure, under specific conditions...you are correct. That has to be at mean sea level and takes into account that gravity on the surface of the earth is a constant. Which it is not. You have terrain correct? > Here is the current official definition of the pound in the U.S., the > same as the definition in the rest of the world. That is just it...the rest of the world. A pound is not a pound in outer space or another planet. Making kilograms = pounds is mixing apples and oranges. > Yes, there are also pounds force. Sure, for engineers. They love to equate apples and oranges for convenience. But, here again it is assuming constant gravity, at mean sea level etc. Then sure you can make and equivalence and then sure you can use it...To be precise the word equal or equal is wrong. They should use equivalent under certain circumstances. They are a recent bastardization, a > unit never well defined before the 20th century--and quite > surprisingly, a unit which even today doesn't have an "official" > definition. That is my point, they are bastardizing it, so it is not correct. In physics and astronomy, you need clarity in measurements. >>However... sorry, kilograms are mass and Newtons are force. > > There are, of course, also kilograms force. The only difference is > that the metric system is still fully supported and updated--and the > keepers of our standards have been telling us for over 40 years to > stop using kilograms force. They were used incorrectly, read above. I was correcting someones definition of Newtons. Newtons are force and they were incorrectly quoted before. My correction stands. N=kg*m/s^2... >Those were the normal units > for thrust in the Russian space program until at least the late 1980s. To quote Werner Von Braun..."our Germans are better than their Germans!" > We also see things like my torque wrench in "meter kilograms"--I've > had it quite a while, but they are still readily available. Take it back, my Snap on guy can get you one for you that says N*m. > (Of course, as > mentioned above, there are no kilograms force in SI, so kilograms > force are never the proper SI units for anything.) Correct. BP >Your link did not work.. > [quoted text clipped - 5 lines] > >(Note no mention of the word force) Note carefully that while the CGPM felt the need to make clear to confused physicists that their standards define the kilogram as a unit of mass, in the very same resolution they endorsed the use of grams force, and made them well-defined units for the first time in history, by adopting a "standard acceleration of gravity" for this purpose. This is not a concept of physics; it is strictly a concept of metrology, serving no other purpose than defining units of force based on units of mass under the influence of earth's gravity. >Taking into account the decision contained in the sanction of the prototypes >of the Metric System, unanimously accepted by the Conférence Générale des [quoted text clipped - 31 lines] >Sure, under specific conditions...you are correct. That has to be at mean >sea level No, there is no "mean sea level" there. I quoted you the definition--it is a unit of mass, defined as an exact fraction of a kilogram. You didn't see any mention of gravity in that official definition, did you? You didn't see any mention of "force," did you? Show us where you see what you are claiming ths "has to be." http://www.ngs.noaa.gov/PUBS_LIB/FedRegister/FRdoc59-5442.pdf Announcement. Effective July 1, 1959, all calibrations in the U.S. customary system of weights and measures carried out by the National Bureau of Standards will continue to be based upon metric measurement standards and, except those for the U.S. Coast and Geodetic Survey as noted below, will be made in terms of the following exact equivalents and appropriate multiples and submultiples: 1 yard= 0.914 4 meter 1 pound (avoirdupois)= 0.453 592 37 kilogram Currently, the units defined by these same equivalents, which have been designated as the International Yard and the International Pound, respectively, will be used by the National Standards Laboratories of Australia, Canada, New Zealand, South Africa, and United Kingdom; thus there will be brought about international accord on the yard and pound by the English-speaking nations of the world, in precise measurements involving these basic units. The same is true of the official definitions of the rest of the world. In Canada, the Weights and Measures Act of 1953. In the U.K., the Weights and Measures Act of 1963. In Australia, in the Weights and Measures Regulation. In Ireland, which was not a part of the 1959 international agreement, see Statutory INstrument No. 91/1976, Weights and measures (metric equivalents) order, 1976, http://www.irishstatutebook.ie/ZZSI91Y1976.html Furthermore, you can look at the way NIST and the NPL and every other national standards agency who has ever dealt with this issue interprets this definition. They interpret it as defining pounds as units of mass. See, for example, the extensive list of conversion factors in the Appendix of NIST Special Publication 811, and note all the instances in which the pounds are units of mass rather than "pounds force" (which are always identified as such in this document, as they should be), http://physics.nist.gov/Pubs/SP811/ If it "has to be at mean sea level," that still makes a very ill-defined unit. The normal acceleration of gravity at mean sea level at the poles, in Gravity Formula 1980, is 9.8321863685 m/s². But the normal acceleration of gravity at mean sea level at the equator is 9.7803267715 m/s². That's a difference of 0.53%, or more than one part in 190. So you need something a lot more specific than "mean sea level." So what are you going to use? The average normal gravity at sea level across the whole earth? That is 9.797645 m/s². Is that a number familiar to you, one you often see used? I doubt it. Furthermore, take the time to ask yourself this simple question: Why in hell do you suppose the law bothers defining a pound in the first place? It takes a real special kind of idiot to think that when we buy and sell goods by weight, we'd want to measure some quantity which varies with the strength of the local gravitational field. We should not do so; we do not do so; we have never done so. >and takes into account that gravity on the surface of the earth is >a constant. Which it is not. You have terrain correct? [quoted text clipped - 30 lines] > >They were used incorrectly, read above. You read it yourself. That "standard acceleration of gravity" serves no other purpose whatsoever, than to define grams force and kilograms force. We often borrow the same value which is official to define kilograms force to also define pounds force, but other values such as 32.16 ft/s² are used for that purpose as well. Nobody--not any international standards organiztion, not any legislative body, not any national standards agency, not any professional organization, has adopted any official definiton of a pound force. > I was correcting someones >definition of Newtons. Newtons are force and they were incorrectly quoted [quoted text clipped - 4 lines] > >To quote Werner Von Braun..."our Germans are better than their Germans!" Werner von Braun also used kilograms force in describing the thrust of his rockets even back in the 1930s when he was still in Germany. The Chinese space program apparently uses kilograms force for this purpose even today (and you can also find them used on some NASA sites today). Gene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ Gentlemen of the jury, Chicolini here may look like an idiot, and sound like an idiot, but don't let that fool you: He really is an idiot. Groucho Marx >Your link did not work.. Try this then http://www.albinoblacksheep.com/flash/youare.swf Hey, Gene, if you are in California... we can discuss this in person. BP >>Your link did not work.. > > Try this then > http://www.albinoblacksheep.com/flash/youare.swf > I was waiting for someone to say that, but yes pounds are force and > slugs are mass. > > Source "An Introduction to Mechanics", Kleppner and Kolenkow, p.65. Again, no. In the British system of weights and measures the pound is a unit of both force and weight, generally referred to as pounds-mass (abbreviated lbm) and pounds-force (lbf) for clarity in scientific discussions. Poundals and slugs are only force and mass respectively. Source, _Theoretical Physics_, Constant, pp62-64. See also: http://www.slcc.edu/schools/hum_sci/physics/tutor/2210/measurements/ From a legal viewpoint, in the United States at least, the pound avoirdupois is defined explicitly as a certain fraction of a kilogram. That would make it a measure of mass rather than force. Traditionally, however, it can be either. SignatureSteve Gray sgray2@cfl.rr.com Sorry Steve, > Again, no. In the British system of weights and measures the pound is a > unit of both force and weight, I guess the British have it wrong too. FORCE=WEIGHT which is diffent than MASS. Let F=ma. Assume W=mg therefore if g=a than F=W. QED by direct proof. generally referred to as pounds-mass > (abbreviated lbm) and pounds-force (lbf) for clarity in scientific > discussions. Poundals and slugs are only force and mass respectively. Like I said Slugs are MASS. The "pound force" she is refering to is the same as a slug. Remeber F=W=mg. > http://www.slcc.edu/schools/hum_sci/physics/tutor/2210/measurements/ This is what I pulled off of the sight. The U.S. pound has officially been defined as a fraction of a kilogram (the SI-metric standard for mass) since 1889; it is therefore a mass. Sorry, Irena Nelson has her head in her a.s. For a PhD it is sad. You can make the two equivalent ONLY under certain conditions. It is not. The pound would be different at sea level than on Mt Everest. MASS does not change (exept when at high speeds close to the speed of light). She is wrong. I would be the same in mass her as I would anywhere in the universe. However, the force I create on the surface of the planet is due to that surfaces distance from the center of mass of that planet and the particular mass of the planet. I don't think I have ever heard of a planet being weighed in pounds, but I often heard of it have XXX kg mass. > From a legal viewpoint, in the United States at least, the pound > avoirdupois is defined explicitly as a certain fraction of a kilogram. > That would make it a measure of mass rather than force. Traditionally, > however, it can be either. Nope, they are giving equivalences and than is not 100% correct. It is convenient to use, but not physically correct. With Physics, precision counts. BP >Sorry Steve, > [quoted text clipped - 8 lines] >Assume W=mg therefore if g=a than F=W. >QED by direct proof. Only with your original faulty premise. >generally referred to as pounds-mass >> (abbreviated lbm) and pounds-force (lbf) for clarity in scientific >> discussions. Poundals and slugs are only force and mass respectively. > >Like I said Slugs are MASS. The "pound force" she is refering to is the >same as a slug. Remeber F=W=mg. What????? A pound force is a unit of force. A slug is a unit of mass in one particular, specialized subsystem of mechanical units used only in calculations. They are not the same thing. They don't even measure the same quantity. They are related by 1 lbf/slug = 1 ft/s². Note that we use slugs precisely because the subsystem in which they are used forms a "coherent" system of units as that term is defined in metrology jargon. That means that for every different quantity, there is only one unit in that system--and that unit is a unitary combination of the base units. In other words, in the only system which includes slugs, there are no pints or gallons of any kind, not U.S. dry, not U.S. liquid, not imperial. The only unit of volume is the cubic foot. There are British thermal units, there are no horsepower. There aren't even any psi, because there are no inches or ounces or miles in the only system which includes slugs. >> http://www.slcc.edu/schools/hum_sci/physics/tutor/2210/measurements/ > [quoted text clipped - 21 lines] >convenient to use, but not physically correct. With Physics, precision >counts. What's this "physically correct" meaning of words? If I know that the product of two quantities is proportional to a third, how do I go about discovering the words whose God-given meanings match each of those quantities? It doesn't cost you any more to pay attention. Where was your mind, when Steven Gray mentioned those poundals? Do you know what a poundal is? Obviously not--so go look it up, idiot. A poundal is the derived unit of force in the oldest coherent foot-pound-second system of units, the absolute fps system. While the gravitational fps system with slugs whcih you mentioned is a 20th century invention, and one which didn't appear in physics textbooks until after 1940 (and has since disappeared from most of them), the poundal has been around since at least 1879. A poundal is the force which will accelerate the BASE UNIT OF MASS in its system at a rate of 1 ft/s² Now, idiot, can you fill in the blank for us: The base unit of mass in this OLDEST coherent system of English units is the __________________. [Hint: it is the 'p' in this fps system.] Here are the English physicists William Thomson (for whom the SI unit of temperature is named) and Peter Guthrie Tate in 1879, from a later reprint as quoted on alt.sci.physics, sci.engr, and sci.physics back in 1998, Message-ID: <6hgfj5$gpd$1@news.fsu.edu> (underscores identify italics in original) "By taking the gravity of a constant mass for the unit of force it makes the unit of force greater in high than in low latitudes. In reality, standards of weight are _masses_, not_ forces_. They are employed primarily in commerce for the purpose of measuring out a definite quantity of matter; not an amount of matter which shall be attracted to the earth with a given force." <... description of merchant using spring scale to defraud or be defrauded depending on latitude, etc ... Jim Carr> "It is therefore very much simpler and better to take the imperial pound ... as the unit of mass, and to derive from it, according to Newton's definition above, the unit of force." This, of course, refers to the absolute fps system with the poundal, invented about that time by James Thomson (brother of William, I think, but I'm not positive of that, probably a mathematician IIRC). This proves that the poundscannot be units of force. Right? Since you have similarly used existence of the later gravitational fps system to prove that pounds cannot be units of mass, that must mean that pounds do not exist. So stop using those figments of your imagination, and you won't open mouth, insert foot in making such silly arguments in the future. Gene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ Gentlemen of the jury, Chicolini here may look like an idiot, and sound like an idiot, but don't let that fool you: He really is an idiot. Groucho Marx Idiot....Okay... > Now, idiot, can you fill in the blank for us: Gene, how about this. You are an a.shole. You wanna discuss, lets discuss. You want to insult...blow it out your a.s. BP You must be an washed up engineer with language like that. Newton is a force. kg is a mass pound is a weight This argument is not going to be solved by you. Moron. BP > Now, idiot, can you fill in the blank for us: Groucho Marx >You must be an washed up engineer with language like that. > [quoted text clipped - 7 lines] > >> Now, idiot, can you fill in the blank for us: What's the matter, Chicolini. Do you need more hints before you are able to fill in that blank? The base unit of mass in this OLDEST coherent system of English units is the __________________. [Hint: it is the 'p' in this fps system.] My next hint is to go poll those professors again. See if any of them know the absolute fps system of units, and the base unit of mass corresponding to the poundal of force. Gene Nygaard >>Like I said Slugs are MASS. > What????? A pound force is a unit of force. Mistyped...has the right idea but input it incorrecltly. A slug is a unit of mass > in one particular, specialized subsystem of mechanical units used only > in calculations. That is what I said, smart guy. They are not the same thing. They don't even > measure the same quantity. They are related by 1 lbf/slug = 1 ft/s². You again are mixing apples and oranges. force is pound mass is slug This is in the system in which I speak. On mars and everywhere in the galaxy (within reasonable speeds) this mass won't change. You are very short sighted to use pounds for mass in other areas like Neptune of Planet X or on your flying saucer. Pound mass would only be good with those constants. Sure they talk about pound force and pound mass. I understand it. But, it is for those people that don't care about the gravity. Obviously, you are one of them. I keep saying it is stupid to by things by weight and in one of your posts you say the same. Go sell steel by weight in Denver. I've calculated the amount of profit possibility. You also pointed out what I said about a particular point where you state that they created a g to use as a constant. That is what I was getting at when I picked the arbitrary point of sea level...It was just an illustrative point...can you comprehend that? It was just to give some point as to what level you may be close to being constant. BP >Sure they talk about pound force and pound mass. I understand it. But, it >is for those people that don't care about the gravity. Obviously, you are >one of them. I keep saying it is stupid to by things by weight and in one >of your posts you say the same. Go sell steel by weight in Denver. I've >calculated the amount of profit possibility. The people who buy and sell steel are smarter than you are, Chicolini. They use the definition of the ambiguous word weight which is appropriate to the context. But let's delve further into this, Chicolini. Let's suppose that I'm a steel merchant just as dumb as you are, and I'm willing to buy and sell steel using pounds force (and short tons force equal to 2000 lbf). I sell you 1000 short tons force of steel in Denver at $300 per short ton force, then you transport it on your magical truck which uses no diesel fuel and you get no pay as a driver and no other transportation costs to Miami, where you sell me 1000 short tons foirce of steel at $300 per short ton force. 1. How much money do you lose on the steel you brought from Denver? 2. How many extra pounds force of steel do you have to acquire to complete the transaction? How many pounds, the normal pounds as units of mass used by real steel merchants, is that in Miami's gravitational field? For the purpose of this hypothetical, you can use normal gravity from Gravity Formula 1980 or something similar. Assume Denver is at an elevation of 1640 m above sea level at 39°43' N 105°1' W, and that Miami is 3 m above sea level at 23°46' N 80°12' W. [to anyone else who peeks in--yes, that's the way I wanted the buying and selling, I didn't misstate it--give BP time to show us how dumb he really is before you put in your two cents' worth] Gene Nygaard See, Gene its not about the discussion. It's about you being an a.shole. I really hope to God that you are not a professor. I've had ones like you and it really is boring. They are at the end of their rope so they feel like they have to degrade the replacements. You are never gonna win any arguments by degrading the competition and taking it personally. My guess is you are either a young a.shole or an old coot. Either way you are insignificant, and I should know better than to waste my time. But, it is fun to see how insulting people get when they are desperate to get there point across. FPS of course stands for pounds. I still maintain that weight is pounds and slugs are mass. You are obviously stuck on some system that you know well historically, but is very much irrelevant today. The fact of the matter is that if I wanted to measure you in quantities of a.sholes. I could do that. You are a mass of 1000 a.sholes. And when you put it into gravity, it becomes an a.shole force. You have a lot of a.shole force, Gene. BP >>Sure they talk about pound force and pound mass. I understand it. But, >>it [quoted text clipped - 35 lines] > > Gene Nygaard >See, Gene its not about the discussion. It's about you being an a.shole. I >really hope to God that you are not a professor. I've had ones like you and [quoted text clipped - 48 lines] >> elevation of 1640 m above sea level at 39°43' N 105°1' W, and that >> Miami is 3 m above sea level at 23°46' N 80°12' W. So, since you claimed to have done similar calculations already, how much money would you lose? Gene Nygaard >>See, Gene its not about the discussion. It's about you being an a.shole. I >>really hope to God that you are not a professor. I've had ones like you and [quoted text clipped - 53 lines] > >Gene Nygaard Maybe I asked the wrong question. Since we know you'd take me up on this offer, you are dumb enough to think you'd come out ahead. So how much do you think you would make, if you sold me all the excess steel you had left over at the same price? Gene Nygaard Dumbshit, we agreed it was stupid to use weight. Man are you obsessed about this mass/weight argument. You can't even see when we were agreeing in the first place. Boy, you can even notice when someone is taking you for a ride. BP >>>See, Gene its not about the discussion. It's about you being an a.shole. >>>I [quoted text clipped - 72 lines] > > Gene Nygaard >Dumbshit, we agreed it was stupid to use weight. Man are you obsessed about >this mass/weight argument. You can't even see when we were agreeing in the >first place. Boy, you can even notice when someone is taking you for a >ride. > >BP The relevant point here is the relative strength of the gravitational field at Miami vs. the gravitational field at Denver. In which of those two places is the acceleration of free fall greater? Gene Nygaard >>>>See, Gene its not about the discussion. It's about you being an a.shole. >>>>I [quoted text clipped - 72 lines] >> >> Gene Nygaard >FPS of course stands for pounds. I still maintain that weight is pounds and >slugs are mass. You are obviously stuck on some system that you know well >historically, but is very much irrelevant today. No. FPS stands for foot-pound-second. There are three completely separate fps systems of units, the absolute fps system, the gravitational fps system, and the engineering fps system. Only one of them includes slugs. There are also inch-pound-second (ips) systems. None of them include slugs either. The fact that slugs are always units of mass does not prove that pounds are always units of force. Nor more than the fact that poundals are always units of force would prove that pounds are always units of mass. The fps system in most common use in the real world is the engineering fps system, which includes neither slugs nor poundals. Since this is not a coherent system, you see many formulas which include a g_c factor. Most importantly, our everyday measurements are not made in the context of any of these specialized subsystems of mechanical units, which are used only to simplify calculations. In most calculations, you can choose to use any of several different ones of these subsystems to aid your calculations, with little or no difference in the complexity of the calculations. None of these systems are used in measuring the weight of steel in pounds mass, in measuring the weight of a bottle of ketchup in pounds mass, or in measuring the weight of a bar of platinum in troy ounces. Note that you can choose not to call this quantity weight, if that makes you happy. Just remember that making that choice does not mean that someone who does not make that choice is making an error. Furthermore, that is your only option. Keep in mind that it is not a viable option to keep calling this weight, but to misapply a definition of weight which is incorrect and wrong in the context. Gene Nygaard "Life's tough. But it's tougher if you're stupid." - John Wayne >>FPS of course stands for pounds. I still maintain that weight is pounds >>and >>slugs are mass. You are obviously stuck on some system that you know well >>historically, but is very much irrelevant today. > > No. FPS stands for foot-pound-second. I was filling in the P, you jackass. > There are three completely separate fps systems of units, the absolute > fps system, the gravitational fps system, and the engineering fps > system. Only one of them includes slugs. > > There are also inch-pound-second (ips) systems. None of them include > slugs either. Not my fault, its their mistake. > The fact that slugs are always units of mass does not prove that > pounds are always units of force. I never said that you idiot. I said that comparing pounds to kilos is wrong. Nobody specified pound mass. See, Gene I can be an a.shole too. Actually, I am a professional one. Do you notice what is not happening here? It is called communication. > The fps system in most common use in the real world is the engineering > fps system, which includes neither slugs nor poundals. That is why NASA lost that mission. Guys like you insisting on using antiquated ideas without unifying a system. , you see many formulas which include a g_c > factor. Why not stick to something more fundamental and forget the g factor? Just remember that making that choice does not mean > that someone who does not make that choice is making an error. That is the first intelligent thing you have said all along. I began by saying it was an argument about semantic, dipshit. (I like this swearing stuff, it is refreshing). Now follow closely, oh master of the mass and weight. Just because someone does not agree with the implementation does not make him an idiot. This is not about any of mass/weight. It is about two men having a pissing contest, that is what you want...not communication. So like I said, blow it out your a.s. BP > "Life's tough. But it's tougher if you're and a.shole." - BP BP what is the point of your diatribe? I for one don't get any of your reasoning. Whether a kilo of lead or a kilo of feathers is weighed, both return a 1,000 grams, and have the same mass. On the moon the weight is a lot different, on Mt Everest or in Death valley it is only slightly different. But no matter where you weight it in the Solar System, the 1,000 grams has not changed mass when it is lighter or heavier. Mass is mass and doesn't change, weight is the measure of gravitational force for that mass, from that planet, moon or star. 1,000 grams on Earth weights about 1 sixth that value on the Moon, and has exactly the same Mass on the Moon as it does on Earth. If it feels like I'm repeating myself then you have understood my point. I just explained this in different ways to increase the chance it percolated. Regards Robert See, Gene its not about the discussion. It's about .... <sniped for obvious reasons> Exactly. The whole thing got out of control because he forgot his manners. It wasn't about that, Bob-of. BP > BP what is the point of your diatribe? > I for one don't get any of your reasoning. [quoted text clipped - 30 lines] > http://www.newsfeeds.com - The #1 Newsgroup Service in the World! > -----== Over 100,000 Newsgroups - 19 Different Servers! =----- >BP what is the point of your diatribe? >I for one don't get any of your reasoning. > >Whether a kilo of lead or a kilo of feathers is weighed, both return a 1,000 grams, and have the same mass. Most people in this thread, including BP, don't have any difficulty with your example. Now, let's look at my bag of sugar, "Net wt. 4 lb (1.81 kg)" as it tells us right on the label. Do you, EvolBob, understand that no matter where you weigh it in the Solar System (or outside it), this 1.81 kg does not change. Do you, EvolBob, understand that no matter where you weigh it, this 4 lb does not change? (Those pounds are, by definition, units of mass exactly equal to 0.45359237 kg.) >On the moon the weight is a lot different, on Mt Everest or in Death valley it is only slightly different. How well do you understand even this part, EvolBob. In particular, how much money would BP lose in the hypothetical I posed in response to his claim he could make money buying and selling steel in Denver and elsewhere. To review, here's the problem I posed to him, found in the message above BP's message to which you replied: But let's delve further into this, Chicolini. Let's suppose that I'm a steel merchant just as dumb as you are, and I'm willing to buy and sell steel using pounds force (and short tons force equal to 2000 lbf). I sell you 1000 short tons force of steel in Denver at $300 per short ton force, then you transport it on your magical truck which uses no diesel fuel and you get no pay as a driver and no other transportation costs to Miami, where you sell me 1000 short tons foirce of steel at $300 per short ton force. 1. How much money do you lose on the steel you brought from Denver? 2. How many extra pounds force of steel do you have to acquire to complete the transaction? How many pounds, the normal pounds as units of mass used by real steel merchants, is that in Miami's gravitational field? EvolBob, are you able to help BP out with these calculations? Or do you think that BP is going to have steel left over after the second transaction? >But no matter where you weight it in the Solar System, the 1,000 grams has not changed mass when it is lighter or heavier. >Mass is mass and doesn't change, weight is the measure of gravitational force for that mass, from that planet, moon or star. >1,000 grams on Earth weights about 1 sixth that value on the M |
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