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holly
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Horrible Homework:
Q. Hydrogen and oxygen in a sample gas have the same temp. This means the hydrogen molecules, on average, have the same:
(a) speed, but less K.E.
(b) K.E., but more speed
(c) speed, but more K.E.
(d) speed and the same K.E.
(e) K.E. but less speed.
I have no idea how to approach this problem. I think it got stuck in our Chapter Review by mistake, but try telling my professor that. He has forbidden me to speak to him, anyway.
I can't get this one, either: If air were a better conductor than it is, at nighttime, the Earth would be:
(a) considerably cooler
(b) considerable warmer
I can't figure it out, because surely, if the air were a better conductor than it is, it would have warmed the Earth so much better during the day, and the thus the loss at night would not be enough to make it too much colder? But ignoring that, it would make it very much cooler, wouldn't it?
One final one: Nellie Newton pours herself a cup of very hot tea. Should she immediately put some spoonsful of ice water in it, or wait until she is just about to drink it, in order to get it cooled down the quickest?
That's just nuts. This is the kind of question that makes people hate physicists, this sort of nonsense. There's just too much open here. I'm SUPPOSED to answer that she should wait right until she wants to drink it, because it's the diff in the two temps that makes it cool at a faster rate. But we could be talking seconds. Maybe she wants to dump it in right away and start sucking it down. I mean, if she puts the water in it right away, seconds after it's poured, the temp diff would be greatest at THAT point and it would cool down fast. While she's waiting around to drink it and waiting to put the ice water in, it's cooling, right? Then it won't go as fast. Aw, it's a bunch of hooey, that kind of question.
Thanking anyone for any help.
Q. Hydrogen and oxygen in a sample gas have the same temp. This means the hydrogen molecules, on average, have the same:
(a) speed, but less K.E.
(b) K.E., but more speed
(c) speed, but more K.E.
(d) speed and the same K.E.
(e) K.E. but less speed.
I have no idea how to approach this problem. I think it got stuck in our Chapter Review by mistake, but try telling my professor that. He has forbidden me to speak to him, anyway.
I can't get this one, either: If air were a better conductor than it is, at nighttime, the Earth would be:
(a) considerably cooler
(b) considerable warmer
I can't figure it out, because surely, if the air were a better conductor than it is, it would have warmed the Earth so much better during the day, and the thus the loss at night would not be enough to make it too much colder? But ignoring that, it would make it very much cooler, wouldn't it?
One final one: Nellie Newton pours herself a cup of very hot tea. Should she immediately put some spoonsful of ice water in it, or wait until she is just about to drink it, in order to get it cooled down the quickest?
That's just nuts. This is the kind of question that makes people hate physicists, this sort of nonsense. There's just too much open here. I'm SUPPOSED to answer that she should wait right until she wants to drink it, because it's the diff in the two temps that makes it cool at a faster rate. But we could be talking seconds. Maybe she wants to dump it in right away and start sucking it down. I mean, if she puts the water in it right away, seconds after it's poured, the temp diff would be greatest at THAT point and it would cool down fast. While she's waiting around to drink it and waiting to put the ice water in, it's cooling, right? Then it won't go as fast. Aw, it's a bunch of hooey, that kind of question.
Thanking anyone for any help.