This simulation shows two materials in thermal contact with one another. Select which materials you want to use (water, iron, etc.), the mass of each material, and the initial temperature. If you set the temperature to the melting or vaporization point, a black vertical slider appears, allowing you to adjust the fraction of the material that is solid/liquid or liquid/gaseous. Click on the play icon in the bottom left corner of the screen to simulate the heat flow between the two materials. After a short while, the equilibrium temperature will be reached. Click the icon again to pause the simulation.

[list=1][*]Setup a situation where the two materials have different temperatures, but there is no phase change. Does your calculation of the equilibrium temperature match the simulation?[/*][*]Can you find a way to completely vaporize 1 kg of ice that starts at 0 degrees?[/*][*]If ice at 0 degrees is put in thermal contact with water at zero degrees, will any of the water freeze? Will any of the ice melt?[/*][*]What determines which way heat will flow?[/*][/list]