Determining the Equilibrium Temperature

Now, for the fun part!

We are now ready to take the ideas of this chapter and make some interesting calculations or useful predictions. This is but another example of energy conservation.

For a thermally isolated system, heat may flow from one object to another but the total heat flow must be zero. Remember, this is nothing new; this is just Energy Conservation. In this context, it is also known as the First Law of Thermodynamics. That is important. For a system of two object, this means

Q1 + Q2 = 0

If there is no change of state, this means

Q1 = c1 m1 T1 = c1 m1 ( Tf - T1i )

Q2 = c2 m2 T2 = c2 m2 ( Tf - T2i )

If there is a change of state, we must include the latent heats involved.

Working many examples is the best way to become comfortable with Equilibrium Temperature problems.

   Click here for an EXAMPLE.

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Change of State

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(c) 2005, Doug Davis; all rights reserved