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adatesman
May 28, 2010, 1:05 AM
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redlude97
May 28, 2010, 1:14 AM
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patto wrote: redlude97 wrote: Wrong. A balance scale still measures weight. It technically compares torques, but that is a whole other topic. The only reason a balance scale works is because of the force exerted on the masses from the gravitation pull of the earth. Take scale into space and it doesn't matter how much mass you put on one end. Arrrg! I knew somebody would try to disagree with me here. Sure it compares torque, torque produced by an objects weight. And sure it needs non negligable gravity to work. However the answer it outputs is the fixed mass of the object being measured. If you wanted to do the engineering calculations you would see that 'g' gravitational accelleration drops out of the calculation, leaving only 'm' mass. Your argument is akin to saying runners stop watch doesn't measure time it measures the number of vibrations of a quartz crystal during the run. http://en.wikipedia.org/wiki/Weighing_scale In reply to: The balance (also balance scale, beam balance and laboratory balance) was the first mass measuring instrument invented. If you choose to continue to argue this fine. I won't. EDIT: Further to the previous argument. There is indeed recognition of the important of measuring MASS accurately in US commerce and not of weight. In reply to: Testing and certification ...Because gravity varies by over 0.5% over the surface of the earth, the distinction between force due to gravity and mass is relevant for accurate calibration of scales for commercial purposes. Usually the goal is to measure the mass of the sample rather than its force due to gravity at that particular location. Traditional mechanical balance-beam scales intrinsically measured mass. But ordinary electronic scales intrinsically measure the gravitational force between the sample and the earth, i.e. the weight of the sample, which varies with location. So such a scale has to be re-calibrated after installation, for that specific location, in order to obtain an accurate indication of mass. Anybody who has ever calibrated a scale would know that an objecy of fixed MASS is used not an object of fixed WEIGHT.
wiki wrote: Although a balance technically compares weights, not masses
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ptlong
May 28, 2010, 1:18 AM
Post #228 of 311
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redlude97 wrote: LOL, from your very own wikipedia link wiki wrote: Although a balance technically compares weights, not masses
Nice cherry pick, but it doesn't support your contention. The balance compares weights and thereby measures mass.
Get it?
(This post was edited by ptlong on May 28, 2010, 1:18 AM)
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patto
May 28, 2010, 1:18 AM
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redlude97 wrote: LOL, from your very own wikipedia link wiki wrote: Although a balance technically compares weights, not masses
So what? The distinction has been adequately explained by two people in this thread and in that wikipedia article. A balance most certainly compares weights. Nobody has doubted that. A typical balance scale will give you an accurate measurement of mass. It will not give you an accurate measurement of weight.
(This post was edited by patto on May 28, 2010, 1:20 AM)
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jt512
May 28, 2010, 1:21 AM
Post #230 of 311
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adatesman wrote: jt512 wrote: ptlong wrote: What exactly was the original question? What is a kilonewton? Edit: Actually, looking at the thread title, the OP asked for a "discussion of [the] meaning of 'kilonewtons'." Well, he got one! Jay So which answer was the correct one then? The "225 pounds, now go away" one or the longer explanation from the article you thought was lame? 
The OP has already answered that question for us, remember? "Jay was right, the article could have stopped after the first sentence."
When you write an article, you need to consider who the audience for that article is. You seem to be completely oblivious to this concept.
Jay
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ptlong
May 28, 2010, 1:32 AM
Post #231 of 311
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patto wrote: ptlong wrote: Or just a different argument. You're saying: here's what NIST says, and they're saying here's what most people think, or, here's what we were taught in school.  I would also argue that when people go buy 2lb of steak what people really are wanting is 2lb mass not weight.
That's an opinion of course. My suspicion is that most people don't think about it since mass and weight are for most practical purposes (like buying steak) the same thing.
But that doesn't change the fact that you all may be arguing about slightly different things.
* * * *
What's a kilonewton (kN)? A thousand newtons. The newton is a derived unit in the SI system. It is the force required to accelerate one kilogram one meter per second squared. A kilogram is the mass of a specific platinum-iridium cylinder kept in France. The meter is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second. And the second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
The kilonewton is approximately equivalent to 225 pounds force.
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adatesman
May 28, 2010, 1:33 AM
Post #232 of 311
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ptlong
May 28, 2010, 1:38 AM
Post #233 of 311
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Yeah, Aric, but that article sucked, don't you agree? Do you think a lousy answer was really what he was asking for?
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jt512
May 28, 2010, 1:51 AM
Post #235 of 311
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adatesman wrote: jt512 wrote: adatesman wrote: jt512 wrote: ptlong wrote: What exactly was the original question? What is a kilonewton? Edit: Actually, looking at the thread title, the OP asked for a "discussion of [the] meaning of 'kilonewtons'." Well, he got one! Jay So which answer was the correct one then? The "225 pounds, now go away" one or the longer explanation from the article you thought was lame? The OP has already answered that question for us, remember? "Jay was right, the article could have stopped after the first sentence." When you write an article, you need to consider who the audience for that article is. You seem to be completely oblivious to this concept. Jay I'll type this slowly so you can understand it, Jay. The OP asked: In reply to: Can someone direct me to a thread or article explaining the practical meaning of kilonewtons for climbers. in a thread titled: In reply to: Discussion of Meaning of Kilonewtons and gave absolutely no indication that he was looking for the quick answer. Rather, the implication of both his post and thread title point to wanting an answer more substantial than "225 pounds".
You're right, Aric. You see, you actually need some combination of experience, intelligence, common sense, and judgment to understand what the information that the questioner really wants and needs is. Here, I'll type this really slowly for you
beau, the OP wrote: and jt512 is right, the article could have stopped at the first line saying 1kn = 225 pounds . . .
Get it Aric? No, I don't suppose you do. Maybe this will help. I'll type it really slowly for you, too.
rgold wrote: I must say I also agree that the referenced article is awful. Surely not what you want to tell a guy who asks what kN on his carabiner means, or at least not the first thing you want to tell him, which would be the conversion to pounds.
So, I'm sorry, Aric—really I am—that you are incapable of tailoring information to the needs of your audience. But some us don't suffer from that liability.
Now, kindly go back to your "lab" and let us perform our function in peace.
Jay
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adatesman
May 28, 2010, 1:51 AM
Post #236 of 311
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ptlong
May 28, 2010, 1:59 AM
Post #237 of 311
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adatesman wrote: ptlong wrote: Yeah, Aric, but that article sucked, don't you agree? Do you think a lousy answer was really what he was asking for? Meh, I liked it well enough. I especially liked the way they did the lead in with the short answer/smartass answer/etc. I thought that did a particularly nice job of highlighting the fact that there's more to it if you were interested in reading further. I agree it could have been shorter, but not knowing who would be reading it I don't have a problem with it being written to a high school/junior high level. As for what the OP was looking for, I'd go with the long answer since that's what he asked for. Probably would have been better had someone who found the linked article lame had gone to the trouble of finding a better one, but alas they decided to go the other route.
Well it seems that the OP, rgold, Jay, and I disagree with you.
By the way, I've been wondering something. Is "poking" members of this forum now part of the job description for moderator?
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jt512
May 28, 2010, 1:59 AM
Post #238 of 311
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adatesman wrote: ptlong wrote: Yeah, Aric, but that article sucked, don't you agree? Do you think a lousy answer was really what he was asking for? Meh, I liked it well enough. I especially liked the way they did the lead in with the short answer/smartass answer/etc. I thought that did a particularly nice job of highlighting the fact that there's more to it if you were interested in reading further. I agree it could have been shorter, but not knowing who would be reading it I don't have a problem with it being written to a high school/junior high level. As for what the OP was looking for, I'd go with the long answer since that's what he asked for. Probably would have been better had someone who found the linked article lame had gone to the trouble of finding a better one, but alas they decided to go the other route.
Aric, he didn't need an article at all. He needed a sentence, and I did give it to him:
jt512 wrote: [T]the kilonewton is a unit of force equal to 224.8 lb.
And you're acting like a complete ass.
Jay
(This post was edited by jt512 on May 28, 2010, 2:01 AM)
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adatesman
May 28, 2010, 2:00 AM
Post #239 of 311
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jt512
May 28, 2010, 2:31 AM
Post #241 of 311
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adatesman wrote: jt512 wrote: adatesman wrote: jt512 wrote: adatesman wrote: jt512 wrote: ptlong wrote: What exactly was the original question? What is a kilonewton? Edit: Actually, looking at the thread title, the OP asked for a "discussion of [the] meaning of 'kilonewtons'." Well, he got one! Jay So which answer was the correct one then? The "225 pounds, now go away" one or the longer explanation from the article you thought was lame? The OP has already answered that question for us, remember? "Jay was right, the article could have stopped after the first sentence." When you write an article, you need to consider who the audience for that article is. You seem to be completely oblivious to this concept. Jay I'll type this slowly so you can understand it, Jay. The OP asked: In reply to: Can someone direct me to a thread or article explaining the practical meaning of kilonewtons for climbers. in a thread titled: In reply to: Discussion of Meaning of Kilonewtons and gave absolutely no indication that he was looking for the quick answer. Rather, the implication of both his post and thread title point to wanting an answer more substantial than "225 pounds". You're right, Aric. You see, you actually need some combination of experience, intelligence, common sense, and judgment to understand what the information that the questioner really wants and needs is. Here, I'll type this really slowly for you beau, the OP wrote: and jt512 is right, the article could have stopped at the first line saying 1kn = 225 pounds . . . Get it Aric? No, I don't suppose you do. Maybe this will help. I'll type it really slowly for you, too. rgold wrote: I must say I also agree that the referenced article is awful. Surely not what you want to tell a guy who asks what kN on his carabiner means, or at least not the first thing you want to tell him, which would be the conversion to pounds. So, I'm sorry, Aric—really I am—that you are incapable of tailoring information to the needs of your audience. But some us don't suffer from that liability. Now, kindly go back to your "lab" and let us perform our function in peace. Jay Do you have some sort of reading comprehension disability Jay?
No, but it seems you do.
In reply to: The guy asked for an article discussing the meaning of kilonewtons and was given one. Your opinion that the article was lame is immaterial to the discussion, as that judgment regarding the quality of the article lies solely with the OP since he's the one who asked for it.
Yah, he said it was worthless after the first sentence, remember?
In reply to: Unless you have some mind-reading superpowers there's no way for you to know for certain just what the OP was looking for.
Well, it was probably just coincidence that I thought that he just needed the conversion to pounds, and it turned out that he did. I get lucky every now and then. Rgold, too, apparently.
Perhaps you should read this article¹.
Jay
¹ Kruger J and Dunning D. Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments. Psychology. 2009; 1:30-46.
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curt
May 28, 2010, 2:51 AM
Post #242 of 311
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jt512 wrote: adatesman wrote: jt512 wrote: adatesman wrote: jt512 wrote: adatesman wrote: jt512 wrote: ptlong wrote: What exactly was the original question? What is a kilonewton? Edit: Actually, looking at the thread title, the OP asked for a "discussion of [the] meaning of 'kilonewtons'." Well, he got one! Jay So which answer was the correct one then? The "225 pounds, now go away" one or the longer explanation from the article you thought was lame? The OP has already answered that question for us, remember? "Jay was right, the article could have stopped after the first sentence." When you write an article, you need to consider who the audience for that article is. You seem to be completely oblivious to this concept. Jay I'll type this slowly so you can understand it, Jay. The OP asked: In reply to: Can someone direct me to a thread or article explaining the practical meaning of kilonewtons for climbers. in a thread titled: In reply to: Discussion of Meaning of Kilonewtons and gave absolutely no indication that he was looking for the quick answer. Rather, the implication of both his post and thread title point to wanting an answer more substantial than "225 pounds". You're right, Aric. You see, you actually need some combination of experience, intelligence, common sense, and judgment to understand what the information that the questioner really wants and needs is. Here, I'll type this really slowly for you beau, the OP wrote: and jt512 is right, the article could have stopped at the first line saying 1kn = 225 pounds . . . Get it Aric? No, I don't suppose you do. Maybe this will help. I'll type it really slowly for you, too. rgold wrote: I must say I also agree that the referenced article is awful. Surely not what you want to tell a guy who asks what kN on his carabiner means, or at least not the first thing you want to tell him, which would be the conversion to pounds. So, I'm sorry, Aric—really I am—that you are incapable of tailoring information to the needs of your audience. But some us don't suffer from that liability. Now, kindly go back to your "lab" and let us perform our function in peace. Jay Do you have some sort of reading comprehension disability Jay? No, but it seems you do. In reply to: The guy asked for an article discussing the meaning of kilonewtons and was given one. Your opinion that the article was lame is immaterial to the discussion, as that judgment regarding the quality of the article lies solely with the OP since he's the one who asked for it. Yah, he said it was worthless after the first sentence, remember? In reply to: Unless you have some mind-reading superpowers there's no way for you to know for certain just what the OP was looking for. Well, it was probably just coincidence that I thought that he just needed the conversion to pounds, and it turned out that he did. I get lucky every now and then. Rgold, too, apparently. Perhaps you should read this article¹. Jay ¹ Kruger J and Dunning D. Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments. Psychology. 2009; 1:30-46.
I love that paper, but then again, there is the Catch-22.
Curt
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milesenoell
May 28, 2010, 3:01 AM
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dugl33 wrote: [Inline Frog_swimming_anim.gif]
I'm not sure what the meaning of the frog is, but I suspect I agree with it.
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milesenoell
May 28, 2010, 3:07 AM
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A better question is what's the meaning of PTFTW?
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shockabuku
May 28, 2010, 3:12 AM
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I own two metric/english tape measures. Just sayin'.
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jt512
May 28, 2010, 3:21 AM
Post #246 of 311
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curt wrote: jt512 wrote: adatesman wrote: Unless you have some mind-reading superpowers there's no way for you to know for certain just what the OP was looking for. Well, it was probably just coincidence that I thought that he just needed the conversion to pounds, and it turned out that he did. I get lucky every now and then. Rgold, too, apparently. Perhaps you should read this article¹. Jay ¹ Kruger J and Dunning D. Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments. Psychology. 2009; 1:30-46. I love that paper, but then again, there is the Catch-22. Curt
Kruger & Dunning wrote: Prediction 1. Incompetent individuals, compared with their more competent peers, will dramatically overestimate their ability and performance relative to objective criteria. Prediction 2. Incompetent individuals will suffer from deficient metacognitive skills, in that they will be less able than their more competent peers to recognize competence when they see it—be it their own or anyone else's. Prediction 3. Incompetent individuals will be less able than their more competent peers to gain insight into their true level of performance by means of social comparison information. In particular, because of their difficulty recognizing competence in others, incompetent individuals will be unable to use information about the choices and performances of others to form more accurate impressions of their own ability. Prediction 4. The incompetent can gain insight about their shortcomings, but this comes (paradoxically) by making them more competent, thus providing them the metacognitive skills necessary to be able to realize that they have performed poorly.
When I first read this, it was an epiphany. It explained every exasperating argument I had ever had on the Internet.
Jay
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curt
May 28, 2010, 3:42 AM
Post #247 of 311
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Since this thread has already gone to hell, I'm almost tempted to readdress this:
USnavy wrote: If you have three cards, two yellow, one orange, all flipped upside down and identical on their back side, and you flip one over revealing a yellow card what are the chances that the next one you choose will be orange?
Curt
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curt
May 28, 2010, 5:34 AM
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USnavy wrote: csproul wrote: patto wrote: curt wrote: And, a "pound force," as used here, is the original and traditional definition of a "pound." The "pound mass" is a mere convenience created much later to allow weights and masses to be used interchangeably here on Earth--where the acceleration due to gravity is pretty much constant. SIGH. You can argue tradition and convenience all you want. 1000 years ago isn't really that relevent when the difference between weight and mass wasn't established. Today. In the modern world. A pound is a unit of mass primarily. A unit of force in the FPS system. Today. In the modern world. A pound force is defined by a pound mass. (which is defined in terms of a kg) Today. In the United States. In US Customary units, a pound is a unit of mass. And yet, if you were to ask 100 people what a pound is (in the US anyway), I bet almost all of them would tell you that a pound is a unit of weight, i.e force and not a unit of mass. If you have three cards, two yellow, one orange, all flipped upside down and identical on their back side, and you flip one over revealing a yellow card what are the chances that the next one you choose will be orange?
As you have posed the question, the answer is one out of two, or 50%. Is that the question you intended to ask?
Curt
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norushnomore
May 28, 2010, 9:11 AM
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curt wrote: Since this thread has already gone to hell, I'm almost tempted to readdress this: USnavy wrote: If you have three cards, two yellow, one orange, all flipped upside down and identical on their back side, and you flip one over revealing a yellow card what are the chances that the next one you choose will be orange? Curt
Yeah, it's a fun one. The correct answer is 2/3 (66.6%)
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USnavy
May 28, 2010, 12:37 PM
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curt wrote: USnavy wrote: csproul wrote: patto wrote: curt wrote: And, a "pound force," as used here, is the original and traditional definition of a "pound." The "pound mass" is a mere convenience created much later to allow weights and masses to be used interchangeably here on Earth--where the acceleration due to gravity is pretty much constant. SIGH. You can argue tradition and convenience all you want. 1000 years ago isn't really that relevent when the difference between weight and mass wasn't established. Today. In the modern world. A pound is a unit of mass primarily. A unit of force in the FPS system. Today. In the modern world. A pound force is defined by a pound mass. (which is defined in terms of a kg) Today. In the United States. In US Customary units, a pound is a unit of mass. And yet, if you were to ask 100 people what a pound is (in the US anyway), I bet almost all of them would tell you that a pound is a unit of weight, i.e force and not a unit of mass. If you have three cards, two yellow, one orange, all flipped upside down and identical on their back side, and you flip one over revealing a yellow card what are the chances that the next one you choose will be orange? As you have posed the question, the answer is one out of two, or 50%. Is that the question you intended to ask? Curt
Sure is. I think most were looking for:
"Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?"
In which its 2/3rds.
(This post was edited by USnavy on May 28, 2010, 12:37 PM)
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Frog_swimming_anim.gif
