Heat Energy and Flow

Thermodynamics Primer:

THERMODYNAMIC LAWS

You can not subvert or change these laws:

The Zeroth Law (0): Systems are in equilibrium when they are at the same temperature.

• System is in it lowest energy state
• No more energy can be extracted from it
• All systems of different temperature will tend to equilibrium when they are no longer thermally isolated.

The First Law (1): Energy is Conserved in a closed system:

• The net flow of energy across some system is equal to the change in energy of that system
• We usually consider work and heat flow as the two kinds of energy

The Second Law (2): The Law of Entropy:

• It is not possible to extract heat-energy from a reservoir and perform work without creating waste heat that does no work.
• The amount of disorder increases
• Things tend toward a state of randomness(this is not the same as chaos)
• You can not go from a disordered system to an ordered system without inputting more energy (this is the most important attribute of the second law)

  Example:

  We can do this
  
  100% of electrical energy converted to heat by pushing a current through a resistive element.

  We can not reverse that process to do this:
  

  In the course of doing the original work we have increased the disorder to the system by heating it. In no way can we recover work of that this disordered system without putting energy into the system.

  or

  

How a heat engine works: