In the following model, two balls of the same size but of different thermal masses are put in different compartments separate by a thermal insulator in the middle. The balls are heated up by shining a light onto them. The light incidents from the upright position and gives an equal amount of energy to the balls. Start the simulation and wait until the two thermometers read the same temperature. Then turn off the light. Select "Graph" to see the changes of temperature readings from the thermometers.

While the simulation is running, turn on the temperature graph. Turn the light on and off several times. If you were to choose from the above two materials to build a wall of a house, which one would you use?

Lights on
See-through Graph Grid Isotherm Heat flux

Right-click to download this model

Important Note: Light radiation from the hot plate is represented by a limited number of rays, each of which travels at a much slower speed than the speed of light. This is a computational approximation that does not reflect the nature of light energy.

Developed by Charles Xie. © 2010- The Concord Consortium.