00:01
In this question, we're going to be dealing with a reversible process, a reversible adiabatic process, that is is centropic.
00:08
So recall that the entropy in general, it is a function of p and v, that is pressure and volume.
00:18
So if we are dealing with an iscentropic process, that is an adiabatic reversible process, the change in the entropy is going to be equal to zero.
00:27
So we are saying partial s, partial p at constant v, d p, plus partial s, partial v at constant p, gv, this is equal to 0 coming from the isentropic principle.
00:45
So if we look at maxwell relationships, saying partial s, partial p at constant v is equal to negative partial v, partial t at constant entropy, and partial s, partial v at constant p is equal to partial p, partial t at constant entropy.
01:08
So if we take these expressions and we substitute them into this equation right here, what we are going to get is dp over p minus the inverse of p, partial p, partial v, partial v at constant s, dv, this should be equal to zero.
01:30
Then if we recall that if we are looking at the isentropic expansion exponent k, which is k is equal to negative v, p, partial p, partial v at constant s, this is this part right here...