Introduction to Heat Transfer

Heat Transfer

Convection, Conduction, Radiation, &
Celsius vs. Kelvin

How heat
moves

Convection, Conduction,
Radiation, & Celsius vs. Kelvin

Heat travels
from HOT to
COLD!

Transfer of heat by the flow of a gas
or liquid.

Molecules move in a circular
motion.

Hot air rises and cool air falls.

Convection

Water boiling on the stove

(HOT water RISES, COLD water
SINKS)

Heater heating a room, or house

(HOT air RISES, COLD air SINKS)

Convection Examples

Transfer of heat when molecules
bump into each other.

Occurs when there is direct
contact or touching.

Mostly between solids.

Conduction

Touching a hot stove and getting
burned.

Cheese melting on a hamburger. The
cheese is TOUCHING the hamburger
patty.

A spoon getting hot in a bowl of soup.
The spoon is TOUCHING the hot soup.

Conduction Examples

Transfer of heat through rays or
waves.

Rays and waves travel in a straight
line.

Rays can travel through a vacuum
(space).

Radiation

The sun warming the earth.
o
The rays travel in a straight line to the earth

A campfire
o
The rays from the fire warm the front part of
your body

A heat lamp warming food.
o The lamp’s rays travel in a straight line to keep
the food warm.

Radiation Examples

Multiple Choice

What happens when a cold drink sits in a hot room?

• It remains cold

• It gets warmer

• It starts boiling

• It starts to freeze

Multiple Choice

When two things are the same temperature:

• They have the same number of molecules

• Their molecules stop moving

• Their molecules move at the same average speed

• Heat transfer between the two things stops

Multiple Choice

When you heat a pot on a stove, the handle gets warm. Which type of heat transfer is responsible?

• Conduction

• Radiation

• Convection

• All of the above

Multiple Choice

A cat is hanging out several feet from a fire in a fireplace. This causes the kitty cat to get warm. The kitty cat is warm because of...

• Convection

• Conduction

• Radiation

• The fur sweater he's wearing!

Multiple Choice

A certain type of decorative lamp contains colored liquids. These liquids form globs that break off and rise to the top of the liquid. The globs rise due to

• Convection

• Conduction

• Radiation

• Globulation

Multiple Choice

Near the ceiling of a room, the air is warmer. The warmer air is rising because of

• Convection

• Conduction

• Radiation

• It was told to by this crazy fool!

Multiple Choice

In a swimming pool, the water near the surface is slightly warmer. The temperature of the water near the top rises because of

• Convection

• Conduction

• Radiation

• Too many dogs being in the pool!

Multiple Choice

A fireman that is at a building that is on fire feels a door and it is hot. Why does his hand feel hot?

• Convection

• Conduction

• Radiation

• The Human Torch was on the other side!

Multiple Choice

In heat transfer, heat always flows from the _______________ object to the _______________ object.

• hotter / colder

• colder / hotter

• hotter / hotter

• colder / colder

Multiple Choice

Which of the following statements is true regarding heat energy?

• The quicker a molecule moves, the colder it is.

• The slower a molecule moves, the warmer it is.

• The quicker a molecule moves, the warmer it is.

• The faster you dance, the quicker you get tired.

Multiple Choice

To measure the temperature difference between two cups of water, you would use a _____.

• measuring cup

• ruler

• thermometer

• balance scale

Celsius is the modern system of measuring
temperature. It fits in with much of the METRIC
system.

Celsius vs. Kelvin

Kelvin is an important scale used in most of SCIENCE.

ABSOLUTE ZERO
(has not been reached yet)

Molecules are ALWAYS MOVING, even if they are in a
solid, or frozen state. However: When Absolute Zero is
reached:

-ALL molecules STOP MOVING
-NO more KINETIC ENERGY

Celsius vs. Kelvin

Celsius vs. Kelvin

Multiple Choice

Which temperature scale has no negative temperatures?

• Celsius

• Fahrenheit 

• Joule

• Kelvin

Multiple Choice

This happens to water at 0 degrees Celsius.

• Boils

• Freezes

• Heats

• All of them

Multiple Choice

This happens to water at 100 degrees Celsius.

• Boils

• Freezes

• Heats

• All of them

Multiple Choice

A temperature scale that is used mostly in United States. 
According to it, water freezes at 32 degrees and boils at 212 degrees.

• Celsius

• Fahrenheit

• Kelvin

• All of them

Multiple Choice

Scientists' favorite temperature scale, because it begins at the absolute coldest anything can get. 

• Celsius

• Fahrenheit

• Kelvin

• All of them

Multiple Choice

The absolute coldest anything can get.

In Celsius it's -273.15 degrees. Or 0 degrees Kelvin.

• Absolute cold

• Kelvin

• Absolute zero

• I don't know

Multiple Choice

Select the temperature in °F

• 90°F

• 100°F

• 40°F

• 30°F

Multiple Choice

The faster molecules move, 

• the higher the temperature

• the less temperature

• the same temperature

• I don't know

Multiple Choice

Look at the activity. Select the temperature it would most likely be in °F

• 20°F

• 30°F

• 60°F

• 80°F

Multiple Choice

Temperature is a measure of the average _____________ energy of the particles of a substance.

• potential

• kinetic

• gravitational

• heat