Thermodynamic Laws![](http://scienceworld.wolfram.com/images/tealtab_topright.gif)
0. If two systems are in thermal equilibrium with a third system, then they must be in thermal equilibrium with each other. 1.
![](http://scienceworld.wolfram.com/physics/timg81.gif)
, where
dE is the energy change,
![](http://scienceworld.wolfram.com/physics/timg83.gif)
is the change in heat,
dW is the work done,
T is the
temperature,
dS is the change in
entropy,
P is the
pressure, and
dV is the volume change. 2. The second law of thermodynamics prohibits the construction of a
perpetual motion machine of `the second kind.' A consequence is the result that
![](http://scienceworld.wolfram.com/physics/timg87.gif)
. 3. As
temperature goes to 0, the
entropy S approaches a constant
![](http://scienceworld.wolfram.com/physics/timg88.gif)
. Combining the first and second laws gives the
combined law of thermodynamics