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On April 19 2011 08:26 Chill wrote:Show nested quote +On April 19 2011 07:48 SirazTV wrote:On April 19 2011 07:38 Chill wrote:On April 19 2011 07:34 SirazTV wrote:
That is an example of a question that is a terrible true or false question. Both answers are wrong as the temperature could be the same or different. But even if it's the same, the zeroth law doesn't tell us that. But then there is not enough information to answer the question. Lack of information =/= false. Read the question and then read the answers. Lack of information does equal false in this case. I don't know how people are confusing this question. It doesn't even state the thermometer is at equilibrium with the liquid, just that it's submerged. The liquid could be ice water and the thermometer could be a hundred degrees. That's not at equilibrium so the zeroth law doesn't tell us anything in this situation.
Basically this. You are not given enough information for the zeroth law to apply, so the answer is false. Pretty easy question as long as you don't overthink it.
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On April 19 2011 10:21 n.DieJokes wrote:Show nested quote +On April 19 2011 10:10 Dragar wrote:On April 19 2011 10:04 n.DieJokes wrote:On April 19 2011 09:04 Dragar wrote:Ah, but DieJokes, the thermometer only has the temperature of the surroundings thanks to the first and second laws.  I don't think it's a very good question but you are probably right, that is what the teacher is trying to get at with the question. Well, not directly right? As I understand it (I'm a first year chem major) the zeroth law came after the other three so it was discovered using the intuitive concepts that followed from the but it is fundamental to all three of them (hence zeroth). So sure you could come up with that from the first two, but the first two don't actually say that. Sort of directly. Thermometers work (i.e. they reach the same temperature as their surroundings) because of the first and second laws. The zeroth law is indeed fundamental, as it gives you a meaning behind temperature in the first place. I get what you're saying, but the zeroth tells us that they will have exactly the same temperature at equilibrium; you can't get that directly from the first or more importantly the second law.
Yes, I don't disagree. But you will have no reason to believe a thermometer is ever in equilibrium with its surroundings without the other laws.
Edit: I saw your edit. Yes, precisely (although we do still need the first law to relate energy to heat!).
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On April 19 2011 10:26 Dragar wrote:Show nested quote +On April 19 2011 10:21 n.DieJokes wrote:On April 19 2011 10:10 Dragar wrote:On April 19 2011 10:04 n.DieJokes wrote:On April 19 2011 09:04 Dragar wrote:Ah, but DieJokes, the thermometer only has the temperature of the surroundings thanks to the first and second laws. I don't think it's a very good question but you are probably right, that is what the teacher is trying to get at with the question. Well, not directly right? As I understand it (I'm a first year chem major) the zeroth law came after the other three so it was discovered using the intuitive concepts that followed from the but it is fundamental to all three of them (hence zeroth). So sure you could come up with that from the first two, but the first two don't actually say that. Sort of directly. Thermometers work (i.e. they reach the same temperature as their surroundings) because of the first and second laws. The zeroth law is indeed fundamental, as it gives you a meaning behind temperature in the first place. I get what you're saying, but the zeroth tells us that they will have exactly the same temperature at equilibrium; you can't get that directly from the first or more importantly the second law. Yes, I don't disagree. But you will have no reason to believe a thermometer is ever in equilibrium with its surroundings without the other laws.
Ah, I get it. lol, I don't have any good response to that, seems like a valid issue... I just assumed the other laws were in effect. It feels to nit picky to me, idk
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the answer is no
the question says WHEN the blah blah blah
but heat takes time to flow from 1 thing to another so at the moment its submerged they wont have the exact same temperature
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On April 19 2011 10:36 n.DieJokes wrote:Show nested quote +On April 19 2011 10:26 Dragar wrote:On April 19 2011 10:21 n.DieJokes wrote:On April 19 2011 10:10 Dragar wrote:On April 19 2011 10:04 n.DieJokes wrote:On April 19 2011 09:04 Dragar wrote:Ah, but DieJokes, the thermometer only has the temperature of the surroundings thanks to the first and second laws. I don't think it's a very good question but you are probably right, that is what the teacher is trying to get at with the question. Well, not directly right? As I understand it (I'm a first year chem major) the zeroth law came after the other three so it was discovered using the intuitive concepts that followed from the but it is fundamental to all three of them (hence zeroth). So sure you could come up with that from the first two, but the first two don't actually say that. Sort of directly. Thermometers work (i.e. they reach the same temperature as their surroundings) because of the first and second laws. The zeroth law is indeed fundamental, as it gives you a meaning behind temperature in the first place. I get what you're saying, but the zeroth tells us that they will have exactly the same temperature at equilibrium; you can't get that directly from the first or more importantly the second law. Yes, I don't disagree. But you will have no reason to believe a thermometer is ever in equilibrium with its surroundings without the other laws. Ah, I get it. lol, I don't have any good response to that, seems like a valid issue... I just assumed the other laws were in effect. It feels to nit picky to me, idk
It is nit picky, but so is physics. 
It's a badly worded question.
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Oh btw updated the OP with how I answered (I said false). Taking the exam almost made me angry because I had a feeling false was the better answer, but that she wanted true.... so dumb. Got it back today and the "correct" answer was true. Going to "ask" her about it on Wednesday during office hours and get owned since she's the prof.
I can see it now...
".... no you don't understand, people on the sc website TOLD ME SO!!!"
edit: btw Chill broke the poll once he posted, it was like 6 true, 1 false at one point.
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On April 19 2011 14:44 Jonoman92 wrote:
Oh btw updated the OP with how I answered (I said false). Taking the exam almost made me angry because I had a feeling false was the better answer, but that she wanted true.... so dumb. Got it back today and the "correct" answer was true. Going to "ask" her about it on Wednesday during office hours and get owned since she's the prof.
I can see it now...
".... no you don't understand, people on the sc website TOLD ME SO!!!"
edit: btw Chill broke the poll once he posted, it was like 6 true, 1 false at one point.
I still think true is the answer that's most in the spirit of the question. Every argument I've heard otherwise is really ballbustingly technical for a true false but gl!
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Calgary25989 Posts
On April 19 2011 14:44 Jonoman92 wrote:
Oh btw updated the OP with how I answered (I said false). Taking the exam almost made me angry because I had a feeling false was the better answer, but that she wanted true.... so dumb. Got it back today and the "correct" answer was true. Going to "ask" her about it on Wednesday during office hours and get owned since she's the prof.
I can see it now...
".... no you don't understand, people on the sc website TOLD ME SO!!!"
edit: btw Chill broke the poll once he posted, it was like 6 true, 1 false at one point.
I can't accept this answer. The word that rubs me the wrong way is "submerged".
Obviously the intent is that when something is submerged in a liquid for long enough, they are at thermal equilibrium. This question makes no statement on time.
Clearly you can see me holding an icecube submerged in a hot glass of coffee and one second later asking this question. Are they the same temperature? Fuck no. Will they be in a minute? Yes of course.
Things don't necessarily need to be the same temperature to be in thermal equilibrium; however, Qin must equal Qout. There is zero energy generation from a thermometer. If the thermometer is hotter than the liquid, there is going to be heat dissipation through conduction, at the minimum. This system isn't in thermal equilibrium.
Yes, it could be in thermal equilibrium, but the question never states that. If we're going to start making assumptions like that, well then you'd better just quit this class because you can just start assuming every system has an efficiency of 0% and thus transfers zero mass and finish your final in 2 seconds.
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On April 20 2011 00:06 Chill wrote:Show nested quote +On April 19 2011 14:44 Jonoman92 wrote:
Oh btw updated the OP with how I answered (I said false). Taking the exam almost made me angry because I had a feeling false was the better answer, but that she wanted true.... so dumb. Got it back today and the "correct" answer was true. Going to "ask" her about it on Wednesday during office hours and get owned since she's the prof.
I can see it now...
".... no you don't understand, people on the sc website TOLD ME SO!!!"
edit: btw Chill broke the poll once he posted, it was like 6 true, 1 false at one point. I can't accept this answer. The word that rubs me the wrong way is "submerged". Obviously the intent is that when something is submerged in a liquid for long enough, they are at thermal equilibrium. This question makes no statement on time. Clearly you can see me holding an icecube submerged in a hot glass of coffee and one second later asking this question. Are they the same temperature? Fuck no. Will they be in a minute? Yes of course. Things don't necessarily need to be the same temperature to be in thermal equilibrium; however, Qin must equal Qout. There is zero energy generation from a thermometer. If the thermometer is hotter than the liquid, there is going to be heat dissipation through conduction, at the minimum. This system isn't in thermal equilibrium. Yes, it could be in thermal equilibrium, but the question never states that. If we're going to start making assumptions like that, well then you'd better just quit this class because you can just start assuming every system has an efficiency of 0% and thus transfers zero mass and finish your final in 2 seconds.
Had a kid in one of my classes try to be a smartass and write assumptions all over his final. He got to retake it because the professor felt bad giving the kid a fail due to one moment of stupidity.
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EPT
