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Re: Thermodynamics B/C
Posted: February 28th, 2019, 2:06 pm
by CookiePie1
CPScienceDude wrote:Kyzumi wrote:Does the beaker inside of the device have to be removable? Having aerogel surrounding the beaker makes it impossible for being able to take it out and putting it back. Will I have to work around that?
The rules say that it must be removable.
I would recommend trying to make a sleeve of sorts to hold the beaker.
Re: Thermodynamics B/C
Posted: February 28th, 2019, 4:56 pm
by freed2003
What law states that a hot and cold object in contact with eachother will eventually reach the same temperature? I thought it was the 0th but the answer key says its the 2nd and I cant see why
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:00 pm
by JoeyC
2nd law- Heat spontaneously flows from hot bodies to cold bodies. Because of this, heat will flow from the hotter body til neither body has more heat then the other; thermal equilibrium.
The 0th law simply states if a=b, b=c, then a=c. It's basically a given law, with little practical use.
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:07 pm
by CookiePie1
JoeyC wrote:2nd law- Heat spontaneously flows from hot bodies to cold bodies. Because of this, heat will flow from the hotter body til neither body has more heat then the other; thermal equilibrium.
The 0th law simply states if a=b, b=c, then a=c. It's basically a given law, with little practical use.
Well the 0th law is still
very important. It's the very principle behind temperature scales.
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:19 pm
by Crimesolver
CookiePie1 wrote:JoeyC wrote:2nd law- Heat spontaneously flows from hot bodies to cold bodies. Because of this, heat will flow from the hotter body til neither body has more heat then the other; thermal equilibrium.
The 0th law simply states if a=b, b=c, then a=c. It's basically a given law, with little practical use.
Well the 0th law is still
very important. It's the very principle behind temperature scales.
It's also the reason why your finger burns when you touch that thermo waTER
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:27 pm
by JoeyC
ehh, I mean, I understand the point of the 0th law, and that the principle is fundamental to life on Earth, but it's also kinda a given. (though I suppose if you get into high enough physics it may not be, but I'm not there yet)
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:32 pm
by UTF-8 U+6211 U+662F
JoeyC wrote:ehh, I mean, I understand the point of the 0th law, and that the principle is fundamental to life on Earth, but it's also kinda a given. (though I suppose if you get into high enough physics it may not be, but I'm not there yet)
Back when we didn't know what heat was, it wasn't obvious that all kinds of heat were the same: just energy. The 0th law allows us to rigorously define temperature scales and the like.
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:42 pm
by freed2003
Wait why does increasing temperature increase entropy if it’s in the denominator for entropy? Also doesn’t decreasing energy decrease entropy even though it’s in the numerator?
Re: Thermodynamics B/C
Posted: February 28th, 2019, 5:45 pm
by UTF-8 U+6211 U+662F
freed2003 wrote:Wait why does increasing temperature increase entropy if it’s in the denominator for entropy? Also doesn’t decreasing energy decrease entropy even though it’s in the numerator?
I think you're getting mixed up here. Heat over temperature is
change in entropy, not total entropy. To answer your questions, it's easiest to use the statistical definition of entropy: the more possible microstates the system could be in, the more entropy the system has. If temperature is increased, the range of speeds that the particles in the system could be going is increased and so entropy is increased. Decreasing energy decreases the range of speeds the particles in the system could be going so entropy is decreased.
Re: Thermodynamics B/C
Posted: March 2nd, 2019, 6:17 pm
by Crimesolver
So here’s the situation: you are given a question where one of the values have 1 sit fig. Those that mean I ACTUALLY have it round to the first sig fig? I find that kinda weird because if the answer is 23.27, I’d have to round it to 20.