Heat Transfer

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Heat Transfer
• Everything is made of molecules.
• When molecules gain energy they
move faster and create more heat.
• (The faster the molecules move the
hotter they are)
• Heat transfer
Evaporation
Melting
Freezing
Condensation
Solid
liquid
Gas
Molecules move
very slowly!
They are close
together.
Molecules move
faster and are
more spread
apart.
Molecules move
very fast! They
are very spread
apart.
Pair/Share
1. What happens to molecules as you add heat?
2. Are the molecules of water moving faster or
slower in cold water? Why
3. Evaporation is when a Liquid turns into a
____________. Heat is __________.
4. Freezing is when a _________ turns into a
____________. Heat is _____________.
5. If the molecules are moving faster and our
more spread out. Was heat added or
removed?
• Heat
• Is the transfer of thermal energy
from a hotter object to a cooler
one until both objects are the
same temperature.
(You can not transfer cold or give
someone cold)
heat transfer video clip
Pair/Share
1. Which direction does heat transfer?
A. From warmer to cooler
B. From cooler to warmer
C. both directions
2. When you touch something cold which
direction is heat being transferred? Why?
3. Explain why you feel cold when you touch
something that is cold.
3 ways that heat is
transferred within the
atmosphere
•Radiation
•Conduction
•Convection
The first method of heat transfer
How does heat energy get from the
Sun to the Earth?
?
RADIATION
• Radiation
• The direct transfer of energy
by infrared electromagnetic
Waves.
What creates
electromagnetic
waves?
• Sun, fire, light bulbs
Video clip 1
video clip 2
Eureka start at 2:30
Pair Share
• Partner A: What is radiation and where
does it come from.
• Partner B: What are three different things
that create electromagnetic radiation?
• Conduction • The direct transfer of
heat from one
substance
to
another
• conduction
substance
that
is
video clip 1
touching.
Ironing Clothes
• Eureka
That’s Hot
Stepping on
hot sand.
• demo of conduction
• flame heating
molecules
Conduction
When you heat a metal strip at one end, the heat travels to the other
end.
As you heat the metal, the particles vibrate, these vibrations make the
adjacent particles vibrate, and so on and so on, the vibrations are passed
along the metal and so is the heat. We call this?
Example of Conduction
Pair Share:
Partner A: Using the picture
on the right explain the
conduction process
Pair Share:
Partner B: Explain how the picture
on the left is conducting heat.
• Convection
• The transfer of heat by
movement of a fluid (liquids and
gases).
• convection video
clip
• Heat video
clips\Convection
2.asf
• ConvectionEureka
Cooking peas in water
OVEN
Dryer
Blow Drying
your Hair.
Water movement
Cools at the
surface
Cooler water
sinks
Convection
current
Hot water
rises
• Heating the
troposphere
• Radiation, conduction and
convection work together to heat
the troposphere.
• Radiation- heats the Earth
• Conduction- Air near earth’s
surface is warmed
• Convection- the warm air
molecules rise and transfer heat
to the cooler air molecules.
Eventually these molecules cool
and sink back down to earth. This
creates Convection Currents.
Radiation, Convection and
Conduction work together to
heat the troposphere.
review of all 3 types
Radiation
Convection Current
Conduction
Review
Heat transfer from a hotter object to a
cooler object until both objects are the
same temperature.
3 types of heat transfer
• Radiation – electromagnetic waves
• Conduction – touching
• Convection- through a fluid (liquid or gas)
• All 3 work together to heat the
troposphere but Convection causes most
of the heating.
Review
Heat transfer from a hotter object to a cooler
object until both objects are the same
temperature.
3 types of heat transfer review, review 2
Music Review
• Radiation – electromagnetic waves
• Conduction – touching
• Convection- through a fluid (liquid or gas)
• All 3 work together to heat the troposphere
but Convection causes most of the heating.
Radiation, Convection and Conduction work
together to heat the troposphere.
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