1. Applications of entropy principle
Transfer of heat through a finite temperature difference
Since

2. Applications of entropy principle
2) Mixing of two fluids

3. And the final temperature is equal to
Since the system is isolated, the heat lost by fluid-1 is equal to the heat gained by fluid-2
And the final temperature is equal to
(Since )
(Since )

4. If m1=m2=m and cp1=cp2=cp, then
(or)
If m1=m2=m and cp1=cp2=cp, then
(Since AM > GM)

5. Maximum work obtainable from two finite bodies at different temperatures

6. Therefore maximum work obtainable is equal to
is minimum when
(or)
Therefore maximum work obtainable is equal to