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#21
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| > If you *must* respond (and I don't see why) then Yes... I will do that from now on. |
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#22
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| [Only registered users see links. ] wrote: In order to be ONE kilogram it must have a weight numerically equal to the acceleration g, at which it will free fall; so that w/g = One! What else would result in ONE? The powers that be have decreed that the kilogram artfact is _one_ even though the figures can't quite justify it. Don |
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#23
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| "Don1" <[Only registered users see links. ]> wrote in message news:1121197131.024496.127050@g44g2000cwa.googlegr oups.com... or maybe 1000kg per m^3. ever notice how, length is calibrated in meters, weight is in g, and volume in l aka dm^3. with these measures, one has to do scaling depending on their basic choice of units (and at the same time, doing such shows that the units are not that well corellated). why all this? if we define density as mass/volume, then there is a problem if the units don't match up. we don't get a nice 1, but some other number. so, with kg/m^3, the density of water is 1000. at the same time, one could also measure mass in terms of Mg, where the density of water, in Mg/m^3, is once again 1. however, it could be argued, the Mg is an "unusual" unit vs the kg and g. yes, it is just a matter of scale, but then again, so is most unit conversion... then again, the g matches with the cm^3, this would make sense, if one decided to measure length in cm. this may or may not be a big deal, after all, many everyday items are measured in cm. once again, density is 1. however, one then has to deal with a world callibrated in cm and g, vs one calibrated in m and kg. one may just have to live with a definition of density of water being 1000 in the case where kg and m are chosen... if one really wanted, they could probably build a whole system of units based off the inch or foot, but this would be both pointless and oddball. such profound effects of all this? nothing really. many would likely regard unit scaling as a rather trivial matter. or whatever... |
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#24
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| Sam Wormley wrote: No, it isn't. To that precision, the maximum density of water at that temperature and pressure is only rho = 0.999 97 g/cm^3 It doesn't surprise me that Eric Weisstein got that wrong, but you should know better, Sam. Geme Nygaard |
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#25
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| Gene Nygaard wrote: Gene, are you going to contact Eric and suggest a correcton? |
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#26
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#27
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#28
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| Gene Nygaard wrote: According to the Handbook of Chemistry and Physics, 76th Edition water has a density of 0.99997 g/cm^3 at 3° C... at 4° C... at 5° C Why don't you provide us with data and error bars to show us how wrong Eric Weisstein is! |
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#29
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#30
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| Tags |
| cubic , decimeter , massdensity , pure , standard , water |
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