Entropy

These are the Temperature vs. Entropy Diagrams for adiabatic, isothermal, isobaric, and isochoric processes. The are under the curve of a T vs. S diagram is the energy of the process.

A miniature Stirling Engine that uses external temperature differences to operate.

The coefficient of performance (cop) is a ratio of what is desired, to the amount of energy or work required to achieve what is desired.

The effectiveness of an engine is a ratio of the actual efficiency to the theoretical efficiency of a carnot engine operating between the same two temperatures.

Using the total change in entropy, and understanding that the change in entropy of the system the "engine" is zero, we can find the final temperature of a mixture of hot and cold water in the same cup. Contrary to our assumption that mixing two equal masses of water, one at boiling and at freezing temperatures, will result in a final temperature of 50 degrees Celsius, we see that the final temperature will actually be 46 degrees Celsius. This is due to a loss of energy as the two water come to equilibrium.

For a carnot engine, the cop can be determined if given the two temperatures the engine will be operating in between. From here, the energy of the hot and cold resevoirs can also be determined.

This here is the calculation of the amount of time needed to freeze 4.20 kg of water at 18 degrees Celsius.

Professor Mason begins an experiment to demonstrate the combustible properties of various gases.

When the bubble is filled with helium, the bubble will float, and even combust if introduced to a large quantity of heat.

The entropy of a system cannot be calculated. However, a change in entropy in reference to a specific state can be measured and is defined as the energy entering or exiting the system over the temperature. These three methods can disrupt the entropy of our classroom.