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Do NOW:
If a cup of coffee and a red popsicle
were left on the table in this room what
would happen to them? Why?
Hmmmm….
Answer
 The
cup of coffee will cool until it
reaches room temperature. The
popsicle will melt and then the
liquid will warm to room
temperature.
Ms Aeschlimann’s
6th Grade
Earth Science
Here is how it works:



Heat Energy IS THE MOVEMENT OF PARTICLES.
It is what makes the coffee hot and the room
warm.
Since the room has a lower temperature than
the coffee, heat energy travels from the coffee
to the room. The opposite happens to the
popsicle. The room is warmer than the popsicle.
So heat energy travels from the room to the
popsicle, first melting it and then warming the
liquid to room temperature.
Heat energy always moves from HOT to COLD !
Now that we know which way heat
energy travels (from hot to cold),
how does it actually travel?
There are three types of heat transfer:
CONDUCTION
• CONVECTION
• RADIATION
•
Conduction


Conduction is transfer of heat
through direct contact.
This is how heat is
transferred to your finger if
you touch a hot stove!
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
Convection



When fluids (liquids and
gases) are heated,
currents are created.
An example of this can be observed in
the air currents that are created in a
room with a radiator against one wall.
The air in contact with the radiator
rises, moves across the ceiling to the
far wall, sinks, and then comes back to
the radiator across the floor.
Water movement
Cools at the
surface
Cooler
water sinks
Convection
current
Hot water
rises
Why is it windy at the seaside?
Joke Break
Radiation

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

Radiated heat energy travels
through empty space.
Electromagnetic waves travel at the speed
of light, which is 300,000,000 meters per
second.
Sometimes these waves are visible, like
when something is “red hot.” You can see
how hot it is, but you can also feel it from
a distance, as your skin absorbs the
energy.
Question: Do you think that radiated heat
needs a material to travel through like
heat transferred by conduction or
convection?
NO!


Electromagnetic
waves do not need a
material to travel
through, although
they can travel
through many
substances.
If this wasn’t true, we
wouldn’t feel the heat
of the Sun here on
Earth!
The third method of heat transfer
How does heat energy get
from the Sun to the Earth?
?
There are no particles
between the Sun and the
Earth so it CANNOT
travel by conduction or
by convection.
RADIATION
Q.) When you put a teapot on
the stove to boil water, which
of the three (3) kinds of heat
transfer can be observed?
Actually, all three!
Here is how…
Conduction
First, there is
Conduction
between the
burner and the
teapot, and then
Conduction
between the
teapot and the
water molecules
that are in direct
contact with the
teapot.
Convection
Next, there is convection
in the water as the
heated molecules of
water from the bottom of
the teapot rise and spread
their heat energy to the
cooler molecules above
them through direct
contact.
This convection current
also pushes cooler
molecules of water down
to the bottom where they
come in contact with the
heated bottom of the
teapot.
Radiation
While all of this is
occurring, heat
energy is being
radiated in all
directions from
the from the
burner and is
absorbed by other
objects. You can
feel this energy if
you stand too
close!
Conduction, Convection and Radiation
HOMEWORK

FIND 3 EXAMPLES OF CONDUCTION,
CONVECTION AND RADIATION AT HOME
AND WRITE THEM DOWN.