Solar Energy Investigation 3:

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Solar Energy Investigation 3 Solar Water Heaters
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• Thinking about heating water.
• How do you think the black collector makes the
  water hotter?
• How do you think the covered container makes the
  water hotter?
• What do you think is the best design for a solar
  water heater? What is your evidence?

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Word Wall Words Absorb- to take up, soak in, or
capture. Reflect- to bounce back. Solar
collector- a material used to capture solar
energy in a water heater or other device.
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Notes on Solar Water Heaters Black plastic
absorbs solar energy, which it transfers to the
water by contact. A cover keeps the heat inside
the container.
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• Part 2 Surface Area
• Lets Review
• Black collectors transferred more heat to the
  water.
• A covered container with a black collector
  produced the hottest water.
• __________________________________________________
  ___
• We know how to make a solar water heater. What
  could you do to get some water even hotter?

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Collector size might affect how hot the water
gets or how fast it heats up. Lets use some new
materials to find out about collector
size. Lets investigate surface area. ( This is
another way of saying how big the collector is)
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If the small collector were considered one unit
of surface area, how many units would the medium
collector be? The large collector? Make a
surface area chart in your notebooks and then
graph your data on your graph sheet. How can we
use our graphs to make predictions on what the
temperature might have been if a collector had
been three units of surface area?
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• Conclusion Questions
• Is there a relationship between the surface area
  of a collector and the temperature of the water?
• What would you change in your water heater design
  to make the water even hotter?

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Word Wall Words Surface area-the total surface
of an object for a rectangle or a square it
equals length times width. Notes Larger
collector surface areas cause the water to heat
up more and faster.
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• Investigation 1
• Part 1 Shadow Play
• Answer the following questions in your science
  journal.
• What is a shadow?
• What do you need in order to have a shadow?
• Do you have one all the time?
• What would happen to your shadow if you stood in
  the same spot all day?

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Investigation 1 Shadow Play What did we learn
from this investigation?

• Shadows are the dark areas that result when light
  is blocked.
• The length of the shadow depends on the position
  and orientation of the Earth relative to the Sun.
• The lenghts of shadows on Earth change as the
  Suns position in the skys changes during the day.