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1. In 3rd step of Carnot cycle, work done on the piston is pdV?

Hm...I got some idea right now. The force –Fpg may not be taken into account in a calculation of the work done on the piston since the origin of this force is the piston itself; the work with –Fpg on the piston may be the work done by the piston itself via the reaction force. It is reminiscent...
2. In 3rd step of Carnot cycle, work done on the piston is pdV?

Hello. I really don't want you to be bothered; But..why is -Fpg same to Fpres ? I think they're different entities. Fpres is from the collisions of gas particles on the piston bottom wall, while Fpg is from the state that the piston is pushing the gas downward. Their origins are different, so...
3. In 3rd step of Carnot cycle, work done on the piston is pdV?

I appreciate your kind comment:) I would like to simply accept your force balancing on the pistol; your drawing really fits what the thermodynamic textbook try to explain. However, I'm still in trouble. Let's have an extension of your drawing. Here, there is another force on the pistol from...
4. Why is entropy a state variable even for irreversible path?

Hello. The entropy S is a state variable or state function as the integral of dS = dQ/T is a path-independent, provided that the path is reversible process path. However, such a path-independency of the integral breaks down when the path includes irreversible process. So, I guess we can only...
5. In 3rd step of Carnot cycle, work done on the piston is pdV?

I see. I think I finally got the right answer. Thanks for all of you to guide me along a right track! I attached the summary of what I've learned from your answers and I hope this would helpful for other guys who have similar question.
6. In 3rd step of Carnot cycle, work done on the piston is pdV?

Hello. I think you suggested me a way to break through my confusion. Yes, the piston is receiving forces from two things simultaneously; one is the external agency pushing the piston by the force Fe, and another one is the gas pushing the piston due to Newton's 3rd law Fgp (external agency...
7. In 3rd step of Carnot cycle, work done on the piston is pdV?

Hello. First, look at the figure describing Carnot's cycle. In 1st step (A → B) and 2nd step (B → C), I fully understand that the work done on the pistol (surrounding) by the gas (system) is dW = pdV where dV = Adl since F = pA is the only force on the pistol from the gas (I assumed there...
8. Can I get description of how heat is realized during fire?

Hello. I've learn that fire is chain-reaction process when burning materials are surrounded by oxygen with enough amount and they're heated exceeding some ignition point. That point is nothing but the temperature above which oxidation between material and oxygen begins. Then during...
9. Ion density in sheath of Langmuir probe in plasma

I've found personal conclusion. First, ion density distribution is obtained by using 1. Current conservation; vi(x)ni(x) = nisvis. 2. Energy conservation; vis = (2eVs/mi)1/2, vi(x) = (2eV(x)/mi)1/2. Combining these two gives ion density in my question. Second, electron has light mass, which...
10. Ion density in sheath of Langmuir probe in plasma

Hello. I'm studying principle of Langmuir probe and got several questions. 1st, the textbook suddenly tells that ion density within sheath is ni(x) = nis(Vs/V(x))1/2 where nis, Vs are ion density and plasma potential at sheath edge. I found some document which shows that it is obtained by...
11. Is there a way to calculate thermal conduction speed or time?

Hello. I'm working in the plasma physics and trying to calculate the thermal conduction time or speed. Thanks to the people here replied my questions, I was able to calculate the thermal conductivity of the plasma with the given electron temperature in SI unit...