First Law of Thermodynamics
How is energy conserved in a system and its environment?
Click each image to learn how it relates to the first law of thermodynamics. Then click the Feature tab.
System and environment
Internal energy
An increase in internal energy
A decrease in internal energy
A thermodynamic system and its enviroment
The internal energy of the system is a result of the potential and kinetic energies of the particles of the gas.
An increased in internal energy
When work is done on the system, W < 0. When energy is transferred to the system as heat, Q>0.
An decrease in internal energy
When work is done by the system, W > 0.
When energy is transferred out of the system as heat, Q<0.
The first law of thermodynamics states that energy is conserved for any system and its environment. Click each image to learn about its relationship to the first law of thermodynamics.
Then click the Feature tab to explore three different kinds of thermodynamic processes.