How can you get the most heat energy from the sun?

How can you get the most heat energy from the sun?

Materials needed

• · Three identical jars
• · Paper and pencil
• · Black paper
• · Aluminum foil
• · Tape
• · Three thermometers
• · Sand

Procedure

1. Fill the three jars with sand.

2. Cover one jar with black paper, including the top,and tape the paper in place.

3. Cover the second jar with aluminium foil, including the top, and the tape the foil in place.

4. Leave the third jar uncovered.

5. Record the temperature shown on the thermometers. Be sure all three indicate the same temperature.

6. Insert one thermometer into the sand in each jar. With the two covered jars, puncture a hole in the top covering and insert the thermometer through the hole.

7. Place all three jars in sunlight. All should receive the same direct sunlight.

8. Check and record the temperature of the three thermometers every 15 minutes for about two hours.

9. How o the temperatures compare? What can you say about the effect of a black surface and a shiny surface on absorption of energy from the sun?

10. Remove the jars from the sunlight and continue to record the temperature of the three thermometers for two more hours.

Questions. How do the temperature changes compare? What can you say about the effect of a black surface and a shiny surface on heat loss?

For problems solvers

 here are more ways to compare the effect of color on heat absorption. Place a thermometer on a paper plate and lay a sheet of black paper over it.

Prepare a second plate using a thermometer and white paper, then a third using aluminum foil. On a warm, sunny day day, place all three plates in direct sunlight. Check and record the temperatures on the thermometers on the thermometers after one-half hour, then again after one hour.

If you live in a cold climate, place papers of various color on snow bank, in the sunlight.use a black paper, a white paper and a piece of aluminum foil of the same size. Use other colors also if you’d like to. Line them up, so the all have direct sunlight. After an hour, check the snow under the papers to find out how much has melted. Check them again after two hours.