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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
Melting
Freezing
Solid
Molecules
move very
slowly! They
are close
together.
Evaporation
Condensation
liquid
Molecules
move faster
and are more
spread apart.
Gas
Molecules
move very
fast! They are
very spread
apart.
• 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
On a hot sunny day, have you ever
seen cars, buildings, or other objects
appear to shimmer or waver on the
other side of a street or parking lot?
• Explanation: Sun is heating up the
ground more quickly than it heats the
air, especially if the surface of the
ground is a dark color. The heated air
rises and bends light waves as it
passes through them. Making the
objects on the other side shimmer.
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
• conduction another substance
video clip 1 that is touching.
• Eureka
Objects
have to
touch!!!
Ironing Clothes
That’s Hot
Stepping on
hot sand.
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?
Conduction Example
• Stir your hot soup with a metal
spoon
• Pretty soon you need a pot holder
because the end of the spoon you
are holding gets hot
• This is heat transfer by
conduction
• Energy travels up the spoon from
the end in the hot soup to the end
in your hand
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
• Convection 2
Cooking peas
in water
Blow Drying
your Hair.
• ConvectionEureka
Dryer
OVEN
Convection
What happens to the particles in a liquid or a gas
when you heat them?
The particles spread out and
become less dense.
This effects fluid movement.
What is a fluid?
A liquid or gas.
Water movement
Cools at the
surface
Cooler
water sinks
Convection
current
Hot water
rises
Why do most refrigerators have the
freezer on top. Hint think about
the principle of convection.
Freezer
compartment
It is put at the
top, because
cool air sinks, so
it cools the food
on the way
down.
It is warmer at
the bottom, so
this warmer
air rises and a
convection
current is set
up.
Conduction, Convection and
Radiation
• 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
Radiation, Convection and Conduction work
together to heat the troposphere.
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.