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#1
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Gene Nygaard wrote: What physical quantity do you think a grocery store scale measures? You can probably figure that out for yourself, if you stop to think about how they are tested and certified. You misunderstand, Gene. It's not at all clear what _you_ think they measure. I'm not asking about the units displayed on them. What physical quantity do you think is actually being measured? And so a torque wrench has what kind of units printed on its scale - mass and distance, or force and distance? Once again, it doesn't cost you any more to pay attention. They are units of force and distance, There's the point. That the poundal system is much older than the slug system is merely one of the many clues as to which is older, the pound mass or the pound force. Ah, older. So that means.........what? 73, Jim AC6XG |
#2
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On Thu, 02 Oct 2003 09:25:38 -0700, Jim Kelley
wrote: Gene Nygaard wrote: What physical quantity do you think a grocery store scale measures? You can probably figure that out for yourself, if you stop to think about how they are tested and certified. You misunderstand, Gene. It's not at all clear what _you_ think they measure. I'm not asking about the units displayed on them. What physical quantity do you think is actually being measured? I think that is probably obvious to anybody with half a brain. But it really doesn't matter, that shouldn't be any impediment to your telling us where my clues have led you. Where are you trying to lead me? Maybe you have some strange notion of what the verb "to measure" means? It wouldn't hurt you to stop and reflect on that for a moment, and answer it at least to yourself, before you get to the "Open mouth, insert foot" stage. And so a torque wrench has what kind of units printed on its scale - mass and distance, or force and distance? Once again, it doesn't cost you any more to pay attention. They are units of force and distance, There's the point. Why are you still refusing to deal with the "meter kilograms" on my torque wrench, even going so far as to dishonestly snip that out from the middle of what you quoted, in between your own comments, without telling us that you were doing so? Since this involves only force and distance, what could it possibly tell you about the existence of a unit of mass called a kilogram? Since this involves only force and distance, what could it possibly tell you about the existence of a unit of mass called a pound? That the poundal system is much older than the slug system is merely one of the many clues as to which is older, the pound mass or the pound force. Ah, older. So that means.........what? Let's not overlook the obvious. Perhaps most the most important thing for your education, and that of several other fools in this thread as well, that it exists. That's something you weren't willing to admit in the beginning. But if it didn't exist, we certainly wouldn't be able to say that it is older. (A corollary, of course, is that if pound force didn't exist, there would be nothing for these units to be older than.) Thus, what you quoted from the appendix of Halliday and Resnick (1981) was incorrect. Do you agree? That it is legitimate. Conversely, that it is the pound force that is the ******* child. This is also one important factor in the usage rules as spelled out by the ASTM and followed by NIST, the U.S. national standards laboratory, and the National Physical Laboratory, the U.K. national standards laboratory. That is indeed one reason why this unit gets to use the unadorned name "pound" and the original symbol "lb," while the newer spinoff needs to be identified as a "pound force" and use the symbol "lbf" to distinguish itself. That the troy pounds, in terms of which the avoirdupois pound was defined for centuries, are units of mass. This doesn't tell you that they have never spawned units of force of the same name; you have to figure that fact out by other means. Gene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ |
#3
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Gene Nygaard wrote:
"Why are you still refusing to deal with the "meter kilograms" on my torque wrench---?" Multiply the meters by 3.28 and multiply the kilograms by 2.2, and you will have torque in their product computed in foot pounds. Or, just multiply the dial reading by 7.22 for ft.lbs. Torque is the product of force and distance. Weight is a force produced by gravity on a particular mass. The indication on a torque wrench is muscle force times lever length. It directly has little relation to gravity in most torque wrench applications. Weight is the easy way to determine mass. Computing mass from collection of acceleration data would be more complicated. M = F/A Best regards, Richard Harrison, KB5WZI |
#5
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Gene Nygaard wrote: It's Jim Kelley who is having great difficulty dealing with these "meter kilograms." Their existence demolishes one of his major arguments. Will he, or any of the others making similar foolish arguments, ever address this? If you have a point, sir, I think it's time you should make it. If your intent is nothing more than to blither inanities, then when will you have your fill? 73 de ac6xg |
#6
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On Fri, 03 Oct 2003 11:01:09 -0700, Jim Kelley
wrote: Gene Nygaard wrote: It's Jim Kelley who is having great difficulty dealing with these "meter kilograms." Their existence demolishes one of his major arguments. Will he, or any of the others making similar foolish arguments, ever address this? If you have a point, sir, I think it's time you should make it. If your intent is nothing more than to blither inanities, then when will you have your fill? You can be pretty dense when you want to be. Here's what you, Jim Kelley, wrote earlier in this thread: Date: Fri, 26 Sep 2003 15:44:09 -0700 Message-ID: Why do you think torque wrenches have the unit 'foot-pounds' printed on them if the pound is a unit of mass? Date: Wed, 01 Oct 2003 10:32:56 -0700 Organization: University of California, Irvine Lines: 53 Message-ID: And so a torque wrench has what kind of units printed on its scale - mass and distance, or force and distance? What was your point in asking these questions? Quite simple. You were offering those "foot-pounds" as proof of the supposed fact that pounds are units of force and not units of mass. In fact, you specifically claimed, by asking a rhetorical question in last Friday's message, that torque wrenches would not have these units on them if a pound is a unit of mass. So my followup to you is along the same lines: Do you claim that those "meter kilograms" prove that kilograms are not units of mass? Not a very difficult question to answer, is it, Jim? Gene Nygaard http://ourworld.compuserve.com/homepages/Gene_Nygaard/ |
#7
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Gene Nygaard wrote: So my followup to you is along the same lines: Do you claim that those "meter kilograms" prove that kilograms are not units of mass? Not a very difficult question to answer, is it, Jim? Nope. As I recall, the reason it came up was that you were denying that pounds were a unit of force. I cited the torque wrench, and you pointed out that kg-f are also units of force. I still think you lose on that account. Don't you? 73 ac6xg |
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