Hello, first of all, I must say that I am quite knowledge lacking in the thermodynamics topic, I am just seeking some intuitions.
From what I have read so far, heat can only flow from hot bodies to cold bodies, and not the way around, according to the 2nd law of thermodynamics.
According to this image,
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which illustrates the transfer of heat between two objects, it seems that when a hot body is placed nearby a cold one, only the hot body irradiates heat to the cold body. Is this actually the case? I ask such because i've also read somewhere that every body irradiates some heat, hence it would make sense for the cold body to send some photons to the hot body.
I would imagine that the cold body also irradiates heat, but since it irradiates less heat than the hot one, the image just ilustrastes that the "effective" heat movement goes from the hot body to the cold body. Am i correct in this point?
My second major question, relates to the subject as a whole. Why is it that an equilibrium between two bodies with diferent temperatures has to be achieved? What in the nature justifies such? I mean, speaking in terms of atoms, electrons and the speed of these, how does the process as a whole work?
I've found an answer to a certain degree in this link
The relevant quote is the following "The answer lies in energy and momentum conservation in a collision - one can show, using these two principles, that in a collision between two objects which conserves energy (called an elastic collision the faster object slows down and the slower object speeds up. "
This means that when the atoms of the hot object (fast ones) colide with the atoms of the cold object (slow ones), the slow ones gain momentum, while the fast ones lose momentum, hence the cold object will get warmer while the hot object will get colder. Still, i can't understand how the process will work to reach its end. What if the atoms of the cold object, the recently accelerated ones, bounce back and colide with the atoms of the hot object once more? Wouldn't they give back the gained momentum and hence keep the cold object cold and the hot object hot? What forces the gained heat to remain in the cold object and not return to the hot one?
Also, when dealing with heat radiation, where the atoms of the objects are not coliding, how does the process work to prevent heat from returning to the hot object?
I'm sorry if im having any kind of confusion or if i am missing something.
Thanks in advance
From what I have read so far, heat can only flow from hot bodies to cold bodies, and not the way around, according to the 2nd law of thermodynamics.
According to this image,
which illustrates the transfer of heat between two objects, it seems that when a hot body is placed nearby a cold one, only the hot body irradiates heat to the cold body. Is this actually the case? I ask such because i've also read somewhere that every body irradiates some heat, hence it would make sense for the cold body to send some photons to the hot body.
I would imagine that the cold body also irradiates heat, but since it irradiates less heat than the hot one, the image just ilustrastes that the "effective" heat movement goes from the hot body to the cold body. Am i correct in this point?
My second major question, relates to the subject as a whole. Why is it that an equilibrium between two bodies with diferent temperatures has to be achieved? What in the nature justifies such? I mean, speaking in terms of atoms, electrons and the speed of these, how does the process as a whole work?
I've found an answer to a certain degree in this link
The relevant quote is the following "The answer lies in energy and momentum conservation in a collision - one can show, using these two principles, that in a collision between two objects which conserves energy (called an elastic collision the faster object slows down and the slower object speeds up. "
This means that when the atoms of the hot object (fast ones) colide with the atoms of the cold object (slow ones), the slow ones gain momentum, while the fast ones lose momentum, hence the cold object will get warmer while the hot object will get colder. Still, i can't understand how the process will work to reach its end. What if the atoms of the cold object, the recently accelerated ones, bounce back and colide with the atoms of the hot object once more? Wouldn't they give back the gained momentum and hence keep the cold object cold and the hot object hot? What forces the gained heat to remain in the cold object and not return to the hot one?
Also, when dealing with heat radiation, where the atoms of the objects are not coliding, how does the process work to prevent heat from returning to the hot object?
I'm sorry if im having any kind of confusion or if i am missing something.
Thanks in advance