Tag Archives: radiation cans

Radiant heat travels in the form of waves. No physical contact between objects is needed to transfer heat by radiation. Students will fill black, white, and silver cans with water, and observe the temperature change in the water when the cans are placed under a bright lamp. The cans are being heated by radiation, and the color of the outer finish of the cans determines the efficiency with which they absorb the heat energy. The white and silver cans reflect most of the rays that strike them (visible and non-visible), so they will heat much more slowly than the black can.

In this experiment, you will compare the ability of different surfaces to radiate thermal energy. Does the color of a surface make a difference in how well it radiates thermal energy? If so, how? The answer to these questions could help you decide what color coffee pot will best keep its heat and what color might be used to radiate heat away from a computer chip. In this experiment, we will compare the thermal radiation ability of two surfaces: silver and black. We’ll do this by filling cans with these surfaces with hot water, then letting the water cool down. We’ll measure the temperature of the water in both cans while they’re cooling down and see if there’s a difference in the rate at which the temperatures decrease.