Back to index  of experiments

Experiment Which Colors Are Hot? Which Are Not?

Problem: Do different colors make a surface heat up faster?

Research: Look up information about temperature, heat, and color.

Hypothesis: Predict which color will cause the surface to heat up faster.
I think that the ___________________ colored surface will heat up faster.

Setting Up the Experiment:

Materials:

• Tempura or Acrylic Paint: red, blue, white, black, yellow, green, orange
• paint brushes or painting sponges
• goose-neck type of desk lamp with incandescent light bulb
• thermometer with Celsius and Fahrenheit scales (a range of -20 to 230F, -30 to 110C is preferred) Safety Note- Use a spirit or alcohol-filled thermometer. Do not use a mercury-filled thermometer. See your science teacher for help if necessary.
• 8 small bricks- the same size
• 8 aluminum pie plates (the disposable type)

Steps:

1. Prepare the surfaces:
• Leave one brick and one pie plate unpainted.
• Paint each of the other 7 bricks a different color. Make sure that each brick has an even layer of paint. Let dry.
• Paint each of the other 7 pie plates a different color. Make sure that each pie plate has an even layer of paint. Let dry.
2. Place the thermometer on top of each of the bricks and recording the starting temperature. They should all be the same, around 70°- 72°F or 22°- 23° C, which is room temperature.
3. Set up the lamp on a table or desk and turn it on. Place one or two of the bricks directly under the beam of light. You may need to adjust the goose-neck so that the light falls directly onto the bricks. Depending on the size of your lamp and the size of the bricks, you may be able to do two bricks at a time or you may have to test them one at a time.
4. Measure and record the temperature of the surface of the bricks every ten minutes. Move the goose-neck away while you use the thermometer to quickly measure the temperature of each brick. Then put the lamp back into position. Do not leave the thermometer on the surface of the bricks.
5. Complete the test for each of the colored bricks, measuring and recording the temperature every ten minutes for a total of 60 minutes.
6. Repeat steps 2 - 5 for the metal pie plates. (You may need to do this on another day.) Record all of your measurements.
7. If time allows, you should do another trial for the bricks and another trial for the metal pie plates. This will make sure that you have enough data and that your results are valid. Record all of your measurements.

Results:
Make charts like these to record your results. Then you can graph the temperature changes over time on line graphs.
 

Temperature Changes on the Brick Surface

Temperature Changes on the Metal Pie Plate Surface

Sample Line Graph:

Conclusion:
Look over your results. What did you find out? Does the color of the surface make a difference? Which color caused the brick to heat up fastest? Which color caused the metal pie plate to heat up faster? Which colors stayed the coolest? How can this information be useful?

Write your conclusion and answer the problem. Tell if your hypothesis was correct or incorrect.