Engineering Thermodynamics/Zeroth Law  From Wikibooks, open
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navigation, search  The Zeroth law of Thermodynamics can be
stated as:  If two thermodynamic systems A and B are in thermal
equilibrium, and B is also in thermal equilibrium with another
system C, then A and C are in thermal equilibrium.   "" If a
body isolated from the other environment is in thermal
equilibrium with one body & is separately in thermal equilibrium
with the another body then three bodies are said to be in the
thermal equilibrium with each other.""  This may seem obvious as
we are quite familiar with this experiment. When we place in a
cup of water (System A) a thermometer (System B) we wait a
period of time until they reach equilibrium then read the
measurement on the thermometer.  It is called the Zeroth Law as
it is not derivable from the other laws and is often useful to
understand the concept before presenting the other laws of
thermodynamics.  It also states that at a