HEAT TRANSFER

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HEAT TRANSFER

• Chapter Four Section Two

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Lesson Objective

• At the end of this section, students will be able
  to
• compare and contrast the three forms of heat
  transfer, and
• explain what causes convection currents in the
  mantle.
• Draw an example of the three forms of heat
  transfer.

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Part One Focus Questions

• What is heat?
• What is heat transfer?
• How is heat transferred?
• What causes ice in my hand to melt?
• Why does my hand feel cold when I hold an ice
  cube in it?

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Heat transfer is the movement of energy from a
warmer object to a cooler object.
COOLER
WARMER
HEAT ENERGY
Heat is the total amount of energy in an object.
Temperature is the measure of the total amount of
energy in an object.
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Video Notes
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Three forms of heat transfer

• Conduction
• Radiation
• Convection

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Conduction

• The transfer of heat by direct contact with a
  heat source.
• Identify the heat source
• Touching a hot stove.
• Holding an ice cube in my hand.

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Video Notes
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Radiation

• The transfer of heat through empty space.
• Ultimate source SUN
• Indirect contact

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Video Notes
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Convection

• The transfer of heat through a fluid.
• Fluid liquid or gas.

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Video Notes
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Check Point Summary

• Heat Energy
• Heat moves from warmer objects to cooler objects.
• There are three (3) forms of heat transfer.
• Heat can be transferred by direct or indirect
  contact with a heat source.

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Video Review
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Focus Questions Revisited

• What is heat?
• What is heat transfer?
• How is heat transferred?
• What causes ice in my hand to melt?
• Why does my hand feel cold when I hold an ice
  cube in it?

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Class Activity

• You are now ready to complete two of your lesson
  objectives
• With a partner, compare and contrast the 3 forms
  of heat transfer. Draw a 3-way Venn diagram or
  chart showing how they are alike and how they are
  different.
• On your own, draw, label and color an example of
  each of the 3 forms of heat transfer (final draft
  quality.)

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Density and Convection Currents

• Chapter Four Section Two
• Part Two

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Focus Questions

• What is density?
• What are convection currents?
• What causes convection currents?
• What is the heat source that causes convection
  currents in the Mantle?

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Convection Currents

• Convection currents are the currents created by
  the transfer or flow of heat through a fluid.
• Convection currents occur whenever there is a
  heat source and fluids present.
• Air
• Ocean
• Home
• Water on a stove

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Convection Currents, Cont.
Can you think of some other examples of
convection currents?
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What 3 things combine to create convection
currents?

• Differences in temperature
• Changes in density
• The force of gravity

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Are You Dense?
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Compare the photos. Each takes up the same volume
of space, but the amount of matter inside the
space is very different. In which area would
you feel most comfortable?
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Convection Currents in the Mantle
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  As anything heats, it rises As it rises, it
cools As it cools, it falls As it falls, it
heats.
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Video Notes Guide

• Watch the video segment from Focus on Earth
  Science called Hot is Hot Cold is Not.
• Write down questions you have as you watch the
  video.
• Watch for the explanation of why ice makes your
  hand feel cold.
• Watch for the explanation of how a hot air
  balloon works.

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Review Focus Questions from parts 1 and 2

• What is heat?
• What is heat transfer?
• How is heat transferred?
• What causes ice in my hand to melt?
• Why does my hand feel cold when I hold ice in it
• What is density?
• What are convection currents?
• What causes convection currents?
• What is the heat source for convection currents
  in the mantle?