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#11
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How is mass measured without acceleration?
Carl 1 Lucky Texan chunk wrote: Since in an alloy both components are in the same place, the gravitational constant will be the same for both components so the ratio of their weight will be the same as the ratio of their masses. Weight seems OK to use here. Chunk "Howard Fairchild" wrote in message ... Dale, Neither, as precisely, it is mass. The weight of an object = m (mass) x g (acceleration of gravity).Weight is the force exerted by the mass of the object due to gravitational attraction. Depending upon where you are on the earth, the weight is not a constant, but mass Always is. (unless you are approaching the speed of light, which isn't likely) Density has a buoyancy effect in the measurement of both mass and weight, where differing densities of equal mass displace different volumes (and masses) of air, but in your case, the difference will be immeasureable. ( I do see the difference in my measurements, as I do take it into account when comparing very precise mass standards) So, it's Mass... More confusing facts: 1 ounce Gold = 31.1035 grams (Troy ounce) Precious metals only are measured in Troy units 1 ounce Aluminum = 28.349523 grams (Avoirdupois ounce) Everything else is in A 1 pound Gold = 12 oz Troy = 373.242 grams 1 pound Aluminum = 16 oz Avoirdupois = 453.592368 grams Howie Metrology is my game. "Don A. Gilmore" wrote in message . .. "Dale Hallmark" wrote in message ... "Don A. Gilmore" wrote in message ... Hi guys: Are karats (like of gold) measured by weight or by volume? Most of what I read implies that karats are measured by weight (24k being pure gold), but that just doesn't make any sense. If karats are determined by weight, you would have to know exactly what the alloying metals were to determine it. If karats were by volume, they would be universal, regardless of alloying elements. Which is right? Don Kansas City Neither weight nor volume. It is a measure of purity. Take the karats and divide by 24 and multiply by 100 and you have percent Gold content. You guys are not following me. The purity has to be measured somehow: either weight or volume. Here's an example. If I take one cubic inch of gold and one cubic inch of aluminum and mix them together I should get two cubic inches of alloy that has a purity of 12 karats (50% of 24), but ONLY if I'm measuring karats by volume. One cubic inch of gold weighs .6969 lbs. One cubic inch of aluminum weighs .0975 lbs. So the total weight of the 2.0 cu. in. of alloy is .6969 + .0975 = .7944 lbs. So the percentage of gold by WEIGHT would be .6969 / .7944 = 87.7% Gold accounts for 87.7% of the total weight of the alloy. This results in a karat of .877 x 24 = 21.05k (by weight) which is nowhere close to the "volumetric" karat of 12k. Now, let's say I mix one cubic inch of gold with one cubic inch of copper. Volumetrically I still have half gold, or 12k. But a cubic inch of copper weighs .3210 lbs. So the total weight of the alloy is .6969 + .3210 = 1.018 lbs. and the percentage of gold by WEIGHT is .6969 / 1.018 = 68.5% = 16.4k So by changing the alloying metal I have considerably changed the karat, if indeed we are to use weight to determine karat, even though the size of the resulting alloy (2.0 cu. in.) is the same. Now do you get what I mean? Don Kansas City -- to reply, change ( .not) to ( .net) |
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#12
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Carl 1 Lucky Texan wrote:
How is mass measured without acceleration? Rotating the masses an measuring the forces is one possibility. Best whishes, Heinrich Butschal Carl 1 Lucky Texan chunk wrote: Since in an alloy both components are in the same place, the gravitational constant will be the same for both components so the ratio of their weight will be the same as the ratio of their masses. Weight seems OK to use here. Chunk "Howard Fairchild" wrote in message . .. Dale, Neither, as precisely, it is mass. The weight of an object = m (mass) x g (acceleration of gravity).Weight is the force exerted by the mass of the object due to gravitational attraction. Depending upon where you are on the earth, the weight is not a constant, but mass Always is. (unless you are approaching the speed of light, which isn't likely) Density has a buoyancy effect in the measurement of both mass and weight, where differing densities of equal mass displace different volumes (and masses) of air, but in your case, the difference will be immeasureable. ( I do see the difference in my measurements, as I do take it into account when comparing very precise mass standards) So, it's Mass... More confusing facts: 1 ounce Gold = 31.1035 grams (Troy ounce) Precious metals only are measured in Troy units 1 ounce Aluminum = 28.349523 grams (Avoirdupois ounce) Everything else is in A 1 pound Gold = 12 oz Troy = 373.242 grams 1 pound Aluminum = 16 oz Avoirdupois = 453.592368 grams Howie Metrology is my game. "Don A. Gilmore" wrote in message ... "Dale Hallmark" wrote in message ... "Don A. Gilmore" wrote in message ... Hi guys: Are karats (like of gold) measured by weight or by volume? Most of what I read implies that karats are measured by weight (24k being pure gold), but that just doesn't make any sense. If karats are determined by weight, you would have to know exactly what the alloying metals were to determine it. If karats were by volume, they would be universal, regardless of alloying elements. Which is right? Don Kansas City Neither weight nor volume. It is a measure of purity. Take the karats and divide by 24 and multiply by 100 and you have percent Gold content. You guys are not following me. The purity has to be measured somehow: either weight or volume. Here's an example. If I take one cubic inch of gold and one cubic inch of aluminum and mix them together I should get two cubic inches of alloy that has a purity of 12 karats (50% of 24), but ONLY if I'm measuring karats by volume. One cubic inch of gold weighs .6969 lbs. One cubic inch of aluminum weighs .0975 lbs. So the total weight of the 2.0 cu. in. of alloy is .6969 + .0975 = .7944 lbs. So the percentage of gold by WEIGHT would be .6969 / .7944 = 87.7% Gold accounts for 87.7% of the total weight of the alloy. This results in a karat of .877 x 24 = 21.05k (by weight) which is nowhere close to the "volumetric" karat of 12k. Now, let's say I mix one cubic inch of gold with one cubic inch of copper. Volumetrically I still have half gold, or 12k. But a cubic inch of copper weighs .3210 lbs. So the total weight of the alloy is .6969 + .3210 = 1.018 lbs. and the percentage of gold by WEIGHT is .6969 / 1.018 = 68.5% = 16.4k So by changing the alloying metal I have considerably changed the karat, if indeed we are to use weight to determine karat, even though the size of the resulting alloy (2.0 cu. in.) is the same. Now do you get what I mean? Don Kansas City Grüße, Heinrich Butschal -- www.juwelen.online-boerse.org www.meister-atelier.de www.schmuckfabrik.de www.medico.butschal.de |
#13
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Would any of those forces be attributes of acceleration or deceleration?
Wouldn't you need to accelerate them up to the rotational velocity? Carl 1 Lucky Texan Ursula Butschal wrote: Carl 1 Lucky Texan wrote: How is mass measured without acceleration? Rotating the masses an measuring the forces is one possibility. Best whishes, Heinrich Butschal Carl 1 Lucky Texan chunk wrote: Since in an alloy both components are in the same place, the gravitational constant will be the same for both components so the ratio of their weight will be the same as the ratio of their masses. Weight seems OK to use here. Chunk "Howard Fairchild" wrote in message ... Dale, Neither, as precisely, it is mass. The weight of an object = m (mass) x g (acceleration of gravity).Weight is the force exerted by the mass of the object due to gravitational attraction. Depending upon where you are on the earth, the weight is not a constant, but mass Always is. (unless you are approaching the speed of light, which isn't likely) Density has a buoyancy effect in the measurement of both mass and weight, where differing densities of equal mass displace different volumes (and masses) of air, but in your case, the difference will be immeasureable. ( I do see the difference in my measurements, as I do take it into account when comparing very precise mass standards) So, it's Mass... More confusing facts: 1 ounce Gold = 31.1035 grams (Troy ounce) Precious metals only are measured in Troy units 1 ounce Aluminum = 28.349523 grams (Avoirdupois ounce) Everything else is in A 1 pound Gold = 12 oz Troy = 373.242 grams 1 pound Aluminum = 16 oz Avoirdupois = 453.592368 grams Howie Metrology is my game. "Don A. Gilmore" wrote in message m... "Dale Hallmark" wrote in message ... "Don A. Gilmore" wrote in message ... Hi guys: Are karats (like of gold) measured by weight or by volume? Most of what I read implies that karats are measured by weight (24k being pure gold), but that just doesn't make any sense. If karats are determined by weight, you would have to know exactly what the alloying metals were to determine it. If karats were by volume, they would be universal, regardless of alloying elements. Which is right? Don Kansas City Neither weight nor volume. It is a measure of purity. Take the karats and divide by 24 and multiply by 100 and you have percent Gold content. You guys are not following me. The purity has to be measured somehow: either weight or volume. Here's an example. If I take one cubic inch of gold and one cubic inch of aluminum and mix them together I should get two cubic inches of alloy that has a purity of 12 karats (50% of 24), but ONLY if I'm measuring karats by volume. One cubic inch of gold weighs .6969 lbs. One cubic inch of aluminum weighs .0975 lbs. So the total weight of the 2.0 cu. in. of alloy is .6969 + .0975 = .7944 lbs. So the percentage of gold by WEIGHT would be .6969 / .7944 = 87.7% Gold accounts for 87.7% of the total weight of the alloy. This results in a karat of .877 x 24 = 21.05k (by weight) which is nowhere close to the "volumetric" karat of 12k. Now, let's say I mix one cubic inch of gold with one cubic inch of copper. Volumetrically I still have half gold, or 12k. But a cubic inch of copper weighs .3210 lbs. So the total weight of the alloy is .6969 + .3210 = 1.018 lbs. and the percentage of gold by WEIGHT is .6969 / 1.018 = 68.5% = 16.4k So by changing the alloying metal I have considerably changed the karat, if indeed we are to use weight to determine karat, even though the size of the resulting alloy (2.0 cu. in.) is the same. Now do you get what I mean? Don Kansas City Grüße, Heinrich Butschal -- to reply, change ( .not) to ( .net) |
#14
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Purity is always defined as the percentage by weight(mass) of the wanted
substance in the mixture. 9 karat gold implies that 100gms or ounces or pennyweights of the alloy contains 3/8 gms, ounces or pennyweights of pure gold. A 10gm piece of 9 carat gold made by alloying 3gm of pure gold with 7gm of aluminium would not have the same volume as a piece made by alloying 3gm of gole with 7gm of osmium (if that were possible); its density would be near 21, The aluminium alloy would be much larger in volume, but would still be 9karat. When percentages are assumed to be by volume, that is indicated by the designation (% v/v). The coresponding (% w/w) is used occasionally, when it is required to make absolutely clear that the weight percentage is implied. Hope that helps to clarify the situation. - G.H.Ireland. -- igor _____________________________________________ Acorn RISC OS4 _____________________________________________ |
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