Should I wear black or white?

Project #1506 on iSENSEProject.org

In this activity, students will investigate the reason that they tend to wear lighter colors in warm weather and darker colors in cooler weather. They will build a model to simulate the transfer of energy involved as they monitor temperature changes and try to interpret why and how color affects heat absorption.

Students will tape a temperature probe to a table and place a black piece of paper over it. Place a lamp with a 100-watt bulb about 10 cm above the paper, and collect temperature readings for 10 minutes. Then, using the probe again after it has reached room temperature, place a piece of white paper over it. Collect data again for 10 minutes. (If a computer with two USBs and two probes are available, students can collect data in one setup; lamp should be placed at the boundary between the two pieces of paper, and the bulb should be the same distance between the probe tips.)

Students will look at the temperature changes from the start to finish and analyze which temperature change was most dramatic. Students will look at the saved visualization and try to find the slope (at straight segments of the graph.)

Lab was developed from the following website:

http://www.vernier.com/experiments/msv/6/absorption_of_radiant_energy/

Guiding Questions:

1. Which color had the largest temperature change over the 10 minute period? Which color had the smallest temperature change? What does the slope of each graph tell you about the temperature variations?

2. Based on your answer to #1, can you explain why it is better to wear light-colored clothing in the summer?

3. Solar panels are used to absorb the sun's radiant energy and convert it to heat. What color do you think would be best for these panels? Can you explain why?

4. Engineers, architects and builders sometimes paint roofs or houses white in hot climates to help reduce the need for air conditioning. Can you explain why in terms of heat transfer?