- #1
cianfa72
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Hi,
reading the interesting Reversible vs Irreversible Gas Compression and Expansion Work insight by @Chestermiller I would like to ask for clarification on some points.
In the second bullet at the beginning
Applying the Newton's third laws to the massless piston we get two things:
Does it make sense ? Thank you.
reading the interesting Reversible vs Irreversible Gas Compression and Expansion Work insight by @Chestermiller I would like to ask for clarification on some points.
In the second bullet at the beginning
my understanding is as follows: consider an ideal gas contained in a cylinder featuring a massless piston. An external force per unit area ##P_{ext}## is applied to the piston through a bunch of (external) bodies.Since, by Newton’s third law, the external force per unit area exerted by the surroundings on the gas is equal to the gas thermodynamic pressure at the interface P.
Applying the Newton's third laws to the massless piston we get two things:
- the force per unit area the piston applies to the external bodies through the piston's outer edge is the same (in module) as the external force per unit area ##P_{ext}##
- the force per unit area the thermodynamic pressure of the gas at the piston's inner edge ##P_I## (i.e. the thermodynamic pressure ##P_I## at the piston internal interface) applies to the piston is the same (in module) as the force the piston applies per unit area on the gas inside the cylinder
Does it make sense ? Thank you.
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