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Math Question... (pg. 2)
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| ChemEnhanced |
| so the final piece has 204g of copper and 196 alloy |
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| cammaxwell |
| quote: | Originally posted by VDub
no...you're reading it wrong...
The 60 and 40% are the copper content of the original 2 pieces...
When they are melted, the resulting piece is 51% copper... |
No, I'm not reading it wrong....the answer is above^^^^ |
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| VDub |
| quote: | Originally posted by cammaxwell
400g x 51% = 204g of copper so...
2 pieces, one 220g and one 180g (220+180=400)
220g x 60% = 132g of copper
180g x 40% = 72g of cooper
132g + 72g = 204g of copper OR 51% of the 400g chunk |
Yah that seems to work out doesn't it...
But where did you get the 220 and 180? |
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| ChemEnhanced |
| 200.8 and 199.2 |
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| cammaxwell |
| Billy told me... |
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| VDub |
| quote: | Originally posted by ChemEnhanced
200.8 and 199.2 |
See????
That's what I got..... |
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| ChemEnhanced |
| quote: | Originally posted by VDub
See????
That's what I got..... |
now look in the back of the math book and get the answer
Copper = 204 Alloy = 196
60%copper (122.4) + 40%alloy (78.4) = 200.8
40%copper (81.6) + 60%alloy(117.6) = 199.2 |
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| cammaxwell |
| quote: | Originally posted by ChemEnhanced
now look in the back of the math book and get the answer
Copper = 204 Alloy = 196
60%copper (122.4) + 40%alloy (78.4) = 200.8
40%copper (81.6) + 60%alloy(117.6) = 199.2 |
What?
60% of 200.8 is 120.48......not 122.4?
....and 40% of 199.2 is 79.68....NOT 81.6? |
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| cammaxwell |
| quote: | Originally posted by ChemEnhanced
now look in the back of the math book and get the answer
Copper = 204 Alloy = 196
60%copper (122.4) + 40%alloy (78.4) = 200.8
40%copper (81.6) + 60%alloy(117.6) = 199.2 |
You guys used the 204g for your calculation, but you have to use the ORIGINAL chuck for that.... |
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| ChemEnhanced |
| quote: | Originally posted by cammaxwell
You guys used the 204g for your calculation, but you have to use the ORIGINAL chuck for that.... |
I have no idea if I am right....just playing with the numbers provided. |
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| ChemEnhanced |
| The entire problem is incorrect as you would loose some weight in the melting process....therefore you would also need to determine how much weight is lost in the melting process. |
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| DigiNut |
That really depends whether or not Billy is running an industrial assembly line. I mean, it's pretty unlikely that he has the equipment sitting around in his basement to melt and fuse copper with perfect efficiency and without introducing any impurities. So I'd have to assume he's working at a plant somewhere.
Assuming that, we still need to know if it's a clean room, like a fab, or a regular factory where the copper slabs have no doubt picked up all sorts of dirt, and the melting process probably leaves a copper residue behind.
Now, since the question explicitly states "the resulting piece", it also clearly suggests a freezing process. Does it go into a freezer, sealed, or is it just left sitting around until it solidifies? If memory serves, copper doesn't sublimate, but the impurities might at the right atmospheric temperature, which means that the resulting solid might actually be slightly more pure than the original liquid.
Finally, how is the determination of purity being made? It's easy enough to weigh the thing, but in order to determine the purity you usually have to melt it down or distill it, which seems to be a pointless exercise here after making the new alloy. And if Billy had to melt down the original two samples just to find out the purity, how can we be sure that he didn't lose some copper in that process, before he even started combining them? Are we assuming a specific loss rate here or are these ideal, perfect (i.e. imaginary) conditions?
More to the point, if Billy already has a scale, which he would have needed to weigh the final sample, why didn't he just weigh the original two samples in the first place instead of going through all this ridiculous hassle? |
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