Let the Sunshine In

Standard VI

Students will understand the source and distribution of energy on Earth and its effects on Earth systems.

Objective 01

Describe the transformation of solar energy into heat and chemical energy on Earth and eventually the radiation of energy to space.

Indicator c

Investigate the conversion of light energy from the sun into heat energy by various Earth materials.

Intended Learning Outcomes:

  1. Use Science Process and Thinking Skills
    1. Observe objects, events and patterns and record both qualitative and quantitative information.
    2. Use comparisons to help understand observations and phenomena.
    3. Evaluate, sort, and sequence data according to given criteria.
    4. Select and use appropriate technological instruments to collect and analyze data.
    5. Plan and conduct experiments in which students may:
      • Identify a problem.
      • Formulate research questions and hypotheses.
      • Predict results of investigations based upon prior data.
      • Identify variables and describe the relationships between them.
      • Plan procedures to control independent variables.
      • Collect data on the dependent variable(s).
      • Select the appropriate format (e.g., graph, chart, diagram) and use it to summarize the data obtained.
      • Analyze data, check it for accuracy and construct reasonable conclusions.
      • Prepare written and oral reports of investigations.
    6. Develop and use classification systems.
    7. Construct models, simulations and metaphors to describe and explain natural phenomena.
    8. Use mathematics as a precise method for showing relationships.
    9. Form alternative hypotheses to explain a problem.

Summary:

Students will conduct an experiment which demonstrates the absorption and reflection of sunlight by measuring the heat flow through various window coverings.

Materials:

  • Access to sunlight (outdoors preferable)
  • Water
  • White paper
  • Scissors
  • Tape
  • Beaker
  • Small pieces (the size of the top of the beaker) of various window coverings such as:
    • Screens
    • Tinted shading (lens from sunglasses will work)
    • Curtain materials (may use more than one type)
    • Window blinds
    • Vinyl window shade
    • Glass (to represent double panes)
  • One Beaker for each type of covering tested
  • Thermometer for each type of covering tested
  • Pen or pencil
  • Paper

Sequence and duration of each part of lesson:

Introduction: 5 to 10 Minutes

Ask students to list different window coverings which they have observed in their home, school, car, or other enclosed structures. Write their ideas on the board and then ask which covering they believe best limits the flow of heat. Which do they think keeps the inside of a home warmest/coolest in the summer/winter? Inform them that the following experiment will help them to answer these questions.

Set-up: 10 to 15 Minutes

Procedure:

  1. Fill each beaker to the same level (at least 3 cm.) with water.
  2. Place a thermometer in each beaker.
  3. Cover the sides with white paper.
  4. Number the beakers.
  5. Cover the top of each beaker with one of the different window coverings.
  6. Set each beaker in a sunny location.
  7. Construct a chart to record the following data:
    • Beaker number
    • Water temperature
    • Type of window covering.

Wait time: Approximately 30 Minutes

Time must be allowed for the water to absorb the heat energy from the sun that passes through the covering. During this period, a teacher may develop an original activity for students or may choose from the following:

  1. Instruct students to construct a hypothesis for each beaker's relative heat absorption. Have them list the beakers in order from what they believe will be the coolest to the one they think will be warmest. They may even be asked to go a step further and predict how many degrees they believe the water temperature in each beaker will increase.
  2. Travel around the school, observing and recording different window coverings, the position of windows relative to the sun's rays, and the relative temperature of the rooms near these windows.

Results and Conclusions: 10 to 15 Minutes

Return to the beakers. To insure uniformity, the teacher should read to the students the new temperature of the water in each beaker and have each student carefully record these results on their chart. Ask students to write their conclusions about which materials best control the flow of heat. Have them answer the following questions:

  1. Which covering would keep an enclosed structure warmest/coolest in the summer/winter?
  2. Which of your hypotheses were correct?

Evaluation:

Determine whether or not the objectives have been met through asking questions relating to the data collected.

Variations:

Students may investigate the absorption of different colors or materials to determine which clothes might be best to wear in the summer or winter. They may also test the quality of various sunglass lenses or brands of sunscreen.