Unit 3 Lesson 3 Energy Transfer Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 3 Energy Transfer Indiana Standards 8.2.1 Recognize and.

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Transcript Unit 3 Lesson 3 Energy Transfer Copyright © Houghton Mifflin Harcourt Publishing Company Unit 3 Lesson 3 Energy Transfer Indiana Standards 8.2.1 Recognize and.

Unit 3 Lesson 3

Energy Transfer Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3

Lesson 3 Energy Transfer

Indiana Standards

8.2.1

Recognize and demonstrate how the sun’s energy drives convection in the atmosphere and in bodies of water, which results in ocean currents and weather patterns.

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Unit 3

Lesson 3 Energy Transfer •

Hot and Cold

How are energy and temperature related?

All matter is made of moving particles and has kinetic energy.

Temperature

is a measure of the average kinetic energy of particles.

• The faster a particle moves, the more kinetic energy it has.

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Unit 3

Lesson 3 Energy Transfer •

How are energy and temperature related?

Thermal energy

particles.

is the total kinetic energy of • Thermal energy depends on the number of particles. • More particles means more thermal energy.

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Unit 3

Lesson 3 Energy Transfer •

How are energy and temperature related?

How does kinetic energy change as particle motion increases and decreases?

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Unit 3

Lesson 3 Energy Transfer

What is thermal expansion?

• As space between particles increases, a substance expands.

• The increase in volume that results from an increase in temperature is called

thermal expansion

.

• Thermal expansion causes a change in the density of a substance.

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Unit 3

Lesson 3 Energy Transfer

What is thermal expansion?

Density is the mass per unit volume of a substance.

• Differences in density caused by thermal expansion can cause movement of matter.

• Movement in the atmosphere, water movement, and rock movement also can be caused by thermal expansion.

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Unit 3

Lesson 3 Energy Transfer

Getting Warm

What is heat?

Heat

is the energy that is transferred between objects that are at different temperatures.

• Objects in contact will transfer energy until temperatures are equal in both objects.

• Energy flows from higher to lower temperatures.

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Unit 3

Lesson 3 Energy Transfer •

Why can the temperatures of land, air, and water differ?

The different rates at which materials become warmer or cooler are due to specific heat. • Materials with a high specific heat require more energy to show an increase in temperature.

• Water has a higher specific heat than land, which means it warms and cools slower than land.

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Unit 3

Lesson 3 Energy Transfer

Heat

How is energy transferred by radiation?

Radiation

is the transfer of energy as electromagnetic waves.

• The sun transfers energy to Earth by radiation.

• Radiation can transfer energy to objects that are not in direct contact.

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Unit 3

Lesson 3 Energy Transfer

How is energy transferred by radiation?

• Energy from the sun travels as waves and is called

electromagnetic radiation.

• Forms of electromagnetic radiation include visible light, infrared radiation, X-rays, and ultraviolet rays.

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Unit 3

Lesson 3 Energy Transfer

How is energy transferred by radiation?

• How does the sun heat Earth?

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Unit 3

Lesson 3 Energy Transfer

Where does radiation occur on Earth?

• The sun is almost 150 million km away but is the major source of energy for processes on Earth.

• Solar radiation can be reflected, scattered, or absorbed.

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Unit 3

Lesson 3 Energy Transfer •

Heating Up

How is energy transferred by convection?

Convection

is the transfer of energy due to the movement of matter.

• Convection occurs because most matter becomes less dense when it gets warmer.

Convection currents form as warm and cool matter rise and fall due to temperature and density differences.

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Unit 3

Lesson 3 Energy Transfer

Where does convection occur on Earth?

• Energy moves through the atmosphere as warm air rises and cool air sinks.

• Ocean water has different densities due to temperature and the amount of salt in the water. • Energy is transferred through rock material from Earth’s core to the surface by convection currents.

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Lesson 3 Energy Transfer •

Ouch!

How is energy transferred by conduction?

Conduction

is the transfer of energy from one object to another object through direct contact.

• When objects touch, their particles interact.

• The greater the energy difference, the faster the transfer of energy by conduction occurs.

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Unit 3

Lesson 3 Energy Transfer

Where does conduction occur on Earth?

• Energy can transfer by conduction from warm ground to cool air at Earth’s surface.

• Warm air can transfer energy to cooler water and cause evaporation. If water vapor transfers energy to air, the water vapor can condense.

• Energy can be transferred in rock by conduction, but very slowly.

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