Heat Transfer

Heat Transfer

Learning Objective:

• We will investigate methods of thermal energy transfers, including conduction, convection, and radiation.

What is Heat?

• Heat is also referred to as thermal energy.

• The form of energy associated with the movement of atoms or molecules in a material.

• The particles of a warmer object move faster than the particles of a cooler object.

• All matter has heat energy – some objects have more or less than others.

Multiple Choice

Which has more thermal energy?

• Boiling water.

• Ice cubes.

Multiple Choice

Which has less thermal energy?

• Boiling water.

• Ice cubes.

What is Heat Transfer?

• The movement of thermal energy from one substance to another.

• 3 types of heat transfer – conduction, convection, and radiation.

• Heat always transfers from substances with more thermal energy to substances with less thermal energy until both substances reach the same temperature.

Example

Warmer air rushes into a refrigerator when the door is open.

What is Thermal Equilibrium?

• The point when substances have reached the same temperature and heat no longer flows between them.

Example

A hot cup of coffee sitting on the counter will reach room temperature after a few hours.

Multiple Select

What were the 3 types of heat transfer?

• Conduction.

• Convection.

• Radiation.

• Revolution.

Multiple Choice

Which direction does heat transfer always occur?

• From more thermal energy to less thermal energy.

• From thermal equilibrium to less thermal energy.

• From less thermal energy to more thermal energy.

Open Ended

Brainstorm: Share an example of thermal equilibrium in your daily life.

What is Conduction?

• The transfer of heat from one substance to another through direct contact.

• Conduction occurs most commonly with solids, but can occur with liquids and gases as well.

• Remember it like this: Conduction = direct contact.

Example

A metal spoon in hot soup.

Example

Ice melting in your hands.

Example

Holding a hot cup of coffee.

Open Ended

Brainstorm: Why do you think Conduction usually occurs between solids most often?

What is Convection?

• The transfer of heat through currents caused by the warming and cooling of liquids or gases.

• Travels through fluid materials – liquids and gases.

• Does not occur in solids because the particles of solids are too tightly packed.

Example

Moving wind or ocean currents.

Example

Heat rising from a chimney.

Example

Cooking popcorn with an air popper.

Open Ended

Brainstorm: Share examples of Convection in your daily life.

What is Radiation?

• The transfer of heat through electromagnetic waves.

• Able to travel through empty space.

• Does not require matter to transfer energy.

Example

Feeling the warmth of the Sun on your face.

Example

Heat given off from a light bulb.

Example

Roasting a marshmallow over a flame.

Open Ended

Brainstorm: Is Radiation the same as nuclear energy?

Test Your Skills

Warning: Questions Ahead

Multiple Choice

A hot air balloon rising into the sky is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

The Sun heating Earth’s atmosphere is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

Steam rising from a cup of hot tea is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

Touching a hot stove is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

Feeling the warmth from a fire is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

Ironing a shirt is an example of...

• Conduction.

• Convection.

• Radiation.

Multiple Choice

This type of Heat Transfer requires no matter.

• Conduction.

• Convection.

• Radiation.

Multiple Choice

This type of Heat Transfer usually occurs between solids.

• Conduction.

• Convection.

• Radiation.

Multiple Choice

This type of Heat Transfer involves liquids and gasses only.

• Conduction.

• Convection.

• Radiation.

Open Ended

Brainstorm: Describe the movement of thermal energy between a hand and a chocolate covered donut.

Open Ended

How can I make this lesson better? Use complete sentences with capitalization and punctuation in your response.