Beacon Lesson Plan Library

Is the Sun our Heater?

Jeanelle Kingry
Santa Rosa District Schools

Description

Why is it warm in Florida and cold in Alaska? Students explore and discover how the sun provides heat to the earth, depending on the surface as well as the angle of the sun's rays. (This lesson focuses on the sun as a source of heat only.)

Objectives

The student knows how the energy of the Sun can be captured as a source of heat and light on Earth (for example, plants, solar panels).

Materials

-A textbook that covers how sunlight affects air temperature
-2 similar pans, one filled with sand and the other with water
-Several styrofoam (or other substance) balls of different sizes
-Several flashlights for student use
-Construction and copy paper for demonstrations
-Chart paper or board
-Crayons, colored pencils, and markers
-Checklist for Formative Evaluation of Presentation (See Associated File)

Preparations

1. On the morning of the lesson, fill one flat pan with sand and another flat pan with water. Place these outside in a sunny spot.
2. Put student names and/or numbers on Checklist. (See Associated File)
3. Gather materials and check that flashlights work.
4. Divide class roster into groups of 4 or 5 students.

Procedures

Note: This lesson focuses on the sun as a source of heat only.

1. Take class outside where you earlier placed a pan with water and a pan with sand.

2. Ask students to guess which one would be warmer.

3. Allow students to touch each and discover if they guessed correctly.

4. Ask students why the temperature is different. Allow students to offer explanations one at a time, steering them to suggest that some surfaces absorb more heat than others.

5. Return to the classroom for further instructions.

6. (optional) Use a textbook that covers how sunlight affects air temperature.

7. Explain to students that our lesson today will help them understand how the energy of the sun can be captured as a source of heat on Earth.

8. Remind students to consider that the temperature of the air is warmer in the afternoons than in the mornings.

9. Ask students to consider why the temperature is different at different times of day. Allow responses.

10. Explain to students that sunlight passes through the air without heating it at all; that it only generates heat when it comes in contact with different surfaces Ė solids and/or liquids such as forests, highways, lakes, grassy areas, etc.

11. Explain to students that the sunís rays warm liquids and solids, and then the heat rises from those objects.

12. Discuss comparisons of asphalt and grass and other surfaces.

13. Explain to students that Earthís surface does not heat evenly; that it depends on the angle of the sunís rays striking the earth.

14. Ask the students why they think that is.

15. Encourage students to decide that the angle at which the sun hits would make a difference. The more direct rays are at noon; they generate more heat.

16. Carry the concept even further by explaining to students that the rays heat the surface (whatever it is), and then the surface warms the air. Encourage students to understand that this is why the temperature is often warmest in the afternoon.

17. Explain to students that you have models for their use in exploring how the sun's rays hit the earth (flashlights, balls, etc.). Place students in groups of 4 or 5 students. Allow groups ten minutes for exploration. Circulate among groups.

18. Instruct groups of students that they have twenty minutes (longer if needed) to prepare a presentation for the class which demonstrates each the following three concepts:
a. The sun warms liquids and solids on the earth, and then the heat rises from those objects warming the air.
b. The earthís surface does not heat evenly; it depends on the angle of the sunís rays as they strike the surface.
c. The air temperatures on the earth are often highest in the afternoon.

19. List these concepts in writing on the board or hang a poster stating them. Emphasize that this is where their grades are coming from.

20. Explain to students that they may use skits, posters, demonstrations, drawings, or any manner that they might choose for their presentations.

21. Provide plenty of materials to encourage creativity.

22. Circulate as the students work on presentations.

23. Allow students to make presentations in groups.

24. As the groups do their presentations, check off each required criteria on the Checklist. (See Associated File)

25. Commend those accomplishing all three criteria, and provide suggestions to those who did not accomplish one or more, emphasizing how they might reach that criteria. The observing class members might even make suggestions.

26. Explain to students that during their free time, center time or at home they might want to check out the sun movie at www.brainpop.com/science/space/sun/index.weml. (See Weblinks)

Assessments

EVIDENCE
Formative assessment is done as students in groups use models to explore how the energy of the sun can be captured as a source of heat on Earth.

At the end of the exploration, each group demonstrates through skits, posters, etc. their knowledge of how the energy of the sun can be captured as a source of heat on Earth.

CRITERIA
In group presentations, students demonstrate (using provided materials) some discovered evidence of use of the sun for heat on Earth demonstrating each of the following:
1. The sun warms liquids and solids on the earth, and then the heat rises from those objects warming the air.
2. The earthís surface does not heat evenly; it depends on the angle of the sunís rays as they strike the surface.
3. The air temperatures on the earth are often highest in the afternoon.

Web Links

Use this sun movie as an extension for students to watch during free time or center time after the lesson.
Brainpop.com

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