Heat Energy Transfer

Heat Energy

Transfer

Heat is a form of energy

that flows from a

warmer material to a

colder one.

HEAT

Definitions of Energy

The term “heat” as used in everyday language
refers both to thermal energy (the motion of
atoms or molecules within a substance) and
energy transfers by convection, conduction,
and radiation (particularly infrared and light).

Multiple Select

Heat... (select all correct answers)

• is a form of energy

• refers to the motion of atoms or molecules within a substance

• flows from a warmer material to a colder one

• is only in your imagination

Imagine a cup of hot chocolate
on a table. If you put some ice

cubes in the hot chocolate drink,
what do you think will happen to

the hot chocolate? What will

happen to the ice cubes?

PICTURE THIS!

The chocolate drink is hot
while the ice cubes are cold.
When mixed, the chocolate
drink cools down and the

ice cubes warm up and melt.

Heat flows from the hot

chocolate to the ice cubes.

Draw

Draw an energy to show how heat flows.

If there is a difference in

temperatures between two

objects, heat flows.

Temperature is a

measurement of how hot or

cold something is.

TEMPERATURE

If you put a scoop of ice
cream into a warm bowl,
what will be the direction

of the flow of heat?

Q

u

e

s

t

i

o

n

Heat flows from an object
with a higher temperature
to one with a lower

temperature. Since the
bowl is warmer than the

ice cream, heat flows from
the bowl to the ice cream.

Poll

Which do you think would transfer the MOST heat energy to ice cream in a cone?

• The sun on a hot summer day

• Your hand holding the cone

• A cold block of ice

• Hurricane force winds

Conservation of Energy and Energy Transfer

Energy is transferred out of hotter regions or objects and into
colder ones by the processes of conduction, convection, and

radiation.

Types of Energy Transfer

Conduction

Convection

Radiation

Frying an egg

Airfryer

Campfire

Heat can flow through a solid. This

movement is called conduction.
Heat is conducted from the hot
end of the solid to its cooler end.

HOW DOES HEAT
FLOW IN SOLIDS?

Energy Transfer in Everyday Life: Conduction

As you cook eggs in a frying pan, the heat
from the stove is transferred to the pan
through direct contact, which is conduction.
The metal of the frying pan is a good
conductor of heat, so it quickly absorbs the
heat energy and distributes it evenly across
the surface of the pan. This causes the
eggs to cook as they come into contact
with the heated surface of the pan.

Multiple Select

Which are examples of conduction? (Select all correct answers.)

• cooking an egg in a pan

• getting a sunburn

• grabbing the handle of a hot pot on the stove and burning your hand

• a mug warms up after hot chocolate is added

HOW DOES HEAT
FLOW IN FLUIDS?

​Heat can flow through a fluid. This movement is called convection. Heated particles move faster and become less dense. Cooled particles move slower, get closer together, become more dense, and are pulled closer to the center of gravity.

​Fluids include liquids and gases.
Liquid rock inside the Earth
moves via convection!

Energy Transfer in Everyday Life: Convection

An air fryer is like a mini oven that uses hot
air to cook food. It has a fan that circulates
the hot air around the food, which cooks it
from the outside first, then inside. This
process is called convection, which means
heat transfer through the movement of a
fluid like air. The hot air transfers heat to the
food's surface, cooking it and creating a
crispy outer layer.

Hot wind
circulates
the food

Multiple Choice

Which one is NOT an example of convection?

HOW DOES HEAT
FLOW IN EMPTY SPACE?

​Heat can flow through empty space. This is called radiation. Heat is moves in the form of electromagnetic radiation (such as light or infrared waves). When the heat waves hit a substance, they transfer energy to the substance and heat them up!

Energy Transfer in Everyday Life: Radiation

Radiation is a way that heat can move
without needing anything to physically
touch or transfer it. It happens when
energy travels through the air or even
empty space. The warmth you feel from
sitting around a campfire at night is from
the heat energy traveling through the air
to reach you.

Word Cloud

List 1 word that you think of when you hear the word "radiation."

Energy Transfer

Energy can be transferred from one system to another
(or from a system to its environment) in different
ways:

• thermally, when a warmer object is in contact with a cooler one

• by electromagnetic waves

• Thermal energy is transferred through a material by the collisions of atoms within the material. Over time, the thermal energy tends to spread out through a material and from one material to another if they are in contact.

• Thermal energy can also be transferred by means of currents in air, water, or other fluids.

• In addition, some thermal energy in all materials is transformed into light energy and radiated into the environment by electromagnetic waves; that light energy can be transformed back into thermal energy when the electromagnetic waves strike another material.

• A material tends to cool down unless some other form of energy is converted to thermal energy in the material.

​Conduction

​Convection

​Radiation

Virtual Experiment! Check out the PhET simulation on the next slide!

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What ways do you see

energy being transferred in

the classroom?

Put your notes away in your binder!

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