Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

24
Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy

Transcript of Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

Page 1: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

Section 2:Transferring Thermal

EnergyChapter 6: Thermal Energy

Page 2: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

WARM-UP: What does it mean to be a

good conductor?

What types of materials are the best conductors?

Page 3: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

LEARNING GOALS Compare the transfer of heat

energy through conduction, convection, and radiation.

Compare and contrast conductors and insulators.

Explain how insulators are used to control the transfer of thermal energy.

Page 4: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

TRANSFERRING THERMAL ENERGY There are 3 ways that

thermal energy is transferred from place to place: Conduction Convection Radiation

Page 5: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONDUCTION

Conduction: transfer of thermal energy by collisions between particles in matter

Think of a metal spoon being heated by a flame.

Page 6: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONDUCTION

Kinetic energy of the particles close to the flame increases.

Those particles collide with the particles close to them and thermal energy is transferred.

Page 7: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.
Page 8: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.
Page 9: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONDUCTION

Conduction occurs when thermal energy is transferred from place to place without the transfer of matter!

Page 10: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

HEAT CONDUCTORS

Heat moves fastest by conduction in solids.

Page 11: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

HEAT CONDUCTORS

Heat moves a little slower by conduction in liquids.

Page 12: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

HEAT CONDUCTORS Heat moves the slowest by

conduction in gases because the particles are so far apart.

Page 13: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

HEAT CONDUCTORS

The best conductors of heat are metals because their electrons flow freely through the metal. Silver, copper, and aluminum

are among the best conductors of heat.

Page 14: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONVECTION

Convection: transfer of thermal energy in a fluid (liquid or gas) by the movement of warmer and cooler fluid from place to place.

Page 15: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONVECTION More energetic

particles collide with less energetic particles and transfer thermal energy.

More energetic particles move faster from place to place.

Page 16: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONVECTION – THE LAVA LAMP Oil is cool and dense

and sits on the bottom of the lamp.

As it warms, the oil expands and becomes less dense than the surrounding fluid.

Page 17: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CONVECTION – THE LAVA LAMP The oil then rises

and loses heat to the surrounding fluid.

It becomes dense again and sinks.

Page 18: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

RADIATION

Radiation: transfer of energy by electromagnetic waves Energy transferred by

radiation is called radiant energy.

Page 19: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

RADIATION

When you stand near a fire to warm your hands, you are warming them using radiation.

Page 20: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.
Page 21: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.
Page 22: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

INSULATORS

Insulator: material that slows down heat transfer

Gases are usually much better insulators than solids or liquids. Conduct heat poorly since

particles are far apart.

Page 23: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

INSULATORS

Examples: fleece jacket and thermos

Page 24: Section 2: Transferring Thermal Energy Chapter 6: Thermal Energy.

CHECK-IN: Would plastic foam (which

contains pockets of air) be a good insulator or good conductor? Explain why.