Second Law - Things to Think About
Thermodynamics | |
---|---|
Introduction | What is this thing called Thermodynamics??? | Definitions | Thermal Equilibrium and Zeroth Law | Limitations |
First Law | Work, Heat, Energy, and the First Law | Work, Heat, Energy, and the First Law (simplied) | Derivatives | Derivatives Exercise | Reversibility, Enthalpy, and Heat Capacity |
Second Law | Things to Think About | Observations and Second Law of Thermodynamics | Alternative Approach - the Clausis Inequality | Consequences of the Second Law | Consequences of the Second Law (simplified) | Carnot Principle - motivation and examples | Equivalence of Second Law Statements* |
Third Law | Third Law of Thermodynamics | Consequences of Third Law* |
Development of Thermodynamics | The Thermodynamic Network | Network Exercise | Equations of State (EOS) | EOS Example, Reading Tables, and Numerical Analysis | EOS Exercises | Thermochemistry |
* Optional Section |
Let us consider the following questions:
- How do we unpeel an orange?
- How do we uncook rice?
- If we have a book on the edge of a table, it will fall off with just a little touch. But it takes a lot more to move a book on the floor up onto a table. Why?
Closer Examination
Let us look the last question a little more. By the first law the amount of energy to move a book from a table to the floor is exactly the same as the amount of energy to move the same book from the floor to the table (same force, same distance). Hence, the first law is not sufficient to account for the difference.
Heart of Thermodynamics
The above questions point to the reason that we need to have a second law of thermodynamics.
The first law of thermodynamics can be handled by the conservation laws in other fields of physics. It is the second law that we need the field of thermodynamics.
The second law of thermodynamics can be called the Heart of Thermodynamics.
Second Law of Thermodynamics
Now that we can see a rationale for a new law of thermodynamics let us continue to a description of the the Second Law of Thermodynamics.