Question of the Day

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Question of the Day.1-13-14

• 1. Does the absorption of sunlight lower or
  increase Earths temperature?
• 2. How does solar energy reach Earth?
• 3. Why should you wear dark clothing in the
  winter, and light clothing in the summer, if you
  work outdoors?

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How is Earths Surface heated?
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Modeling the Absorption of Light

• Hypothesize Which color will be the hottest?
• 1. Place an aluminum pan under a light
• whose light is pointed downward.
• 2. Place two different colors of construction
• paper into the pan. One color should be dark,
• the other a light color.
• 3. Insert a thermometer on top of each
• piece of paper. Record the temperature of each.
• 4. Let the papers sit under the lamp for five
• minutes.
• How does the temperature change?
• Why is one temperature higher than the other?

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Key Terms

• Radiant Energy energy given off by the Sun that
  can travel through empty space.
• Radiation movement of the Suns energy through
  empty space.
• Absorb To take in
• Reflect To bounce back

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What kind of energy is sunlight?

• Have you ever walked barefoot across a sidewalk
  on a sunny day? Did your foot feel the warmth of
  the hot pavement?
• The sidewalk was heated as it absorbed the Suns
  energy.
• Sunlight is an example of
• radiant energy.
• Your foot burned due to Conduction.

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Radiation

• When energy is absorbed by a surface, the surface
  becomes heated. This is why you are able to feel
  the suns rays on your skin when you stand in the
  sun.
• Your skin absorbs the radiation, causing your
  skins molecules to move a little faster.
• RADIATION IS THE TRANSFER OF ENERGY AS
  ELECTROMAGNETIC WAVES!

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Absorption of Energy

• Dark surfaces absorb or take in light.
• When sunlight is absorbed, it is usually
  changed into heat.
• Dark colored objects become hotter than light
  colored objects.
• Light colored objects reflect, or bounce back
  sunlight. They are cooler.

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Hypothesize

• Which do you think will absorb more heat from the
  sun, land or water?

Land
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Decide whether each item listed will absorb or
reflect radiant energy. Write A for absorb or R
for reflect in the space provided.

• 1. cream-colored sweater
• 2. black suit
• 3. concrete sidewalk
• 4. white shirt
• 5. tar-covered street
• 6. dark green tent

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Energy from the Sun

• Only a small part of the Suns
• energy reaches Earth.
• Some of the Suns energy is absorbed by the
  atmosphere.
• Clouds, dust particles and water droplets in the
  atmosphere reflect some of the Suns energy.
• The energy that is reflected goes back into space.

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Energy from the Sun

• Some of the energy that passes
• through Earths atmosphere is absorbed or
  taken in by Earths surface.
• This energy is changed into heat. As a result,
  Earth becomes warmer.
• Create a graphic organizer showing how Earths
  Surface is heated. Use the diagram on the next
  slide.

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Do you Remember?

• Light is a type of ________.
• The Suns energy reaches Earth by __________.
• When light is __________, it turns into heat.
• Clouds, ________ _________ and water droplets can
  reflect, or absorb radiant energy.
• Predict If there were no wind, would it be
  cooler on a sunny day or a cloudy day?