Heat Transfer How does the energy move from

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Heat Transfer How does the energy move from a hotter to a colder object?

Heat Transfer How does the energy move from a hotter to a colder object? Three ways/types/mechanisms 1. 2. 3. Conduction Convection Radiation

Conductio n l This is heat transfer by touching! l One molecule hits another

Conductio n l This is heat transfer by touching! l One molecule hits another and increases it’s motion. (atoms or molecules interact) l The flow of thermal energy through a substance from a higher- to a lower-temperature

Conduction Example Stir your hot soup with a metal spoon Energy travels up the

Conduction Example Stir your hot soup with a metal spoon Energy travels up the spoon from the end in the hot soup to the end in your hand Pretty soon you need a pot holder because the end of the spoon you are holding gets hot

How does these show Conduction? Heat from foot goes to warm cold floor Pan

How does these show Conduction? Heat from foot goes to warm cold floor Pan touch burner (conduction)--Food touch pan (conduction) & food molecules cook Oven mit protects hand from conduction

Convectio n l Heat Transfer in FLUIDS (GAS OR LIQUID) l the GAS OR

Convectio n l Heat Transfer in FLUIDS (GAS OR LIQUID) l the GAS OR LIQUID itself is set into motion called a current l These moving fluid currents are convection

Convection heat transferred by… the of a fluid

Convection heat transferred by… the of a fluid

Convection at home l l When the radiator heats the air, it becomes less

Convection at home l l When the radiator heats the air, it becomes less dense and rises Cool air moves in to replace the air that rose This generates the air flow The rising air cools until its density matches that of the surrounding air

Convection outside l Explains why breezes come from the ocean in the day and

Convection outside l Explains why breezes come from the ocean in the day and from the land at night

Radiation l l Energy carried by electromagnetic waves that can TRAVEL Through EMPTY SPACE!

Radiation l l Energy carried by electromagnetic waves that can TRAVEL Through EMPTY SPACE! radio waves, microwaves, infrared, VISIBLE LIGHT, ultraviolet, x-rays, gamma

Radiatio n l l l “Without the sun there would be no weather, food

Radiatio n l l l “Without the sun there would be no weather, food & life!” The sun’s radiates energy as ultraviolet, infrared, and visible If you were standing next to the camp stove, you would be warmed by the radiation given off by flame.

Radiation examples Heat radiates from camp fire to cook marshmallow Heat from stove radiates

Radiation examples Heat radiates from camp fire to cook marshmallow Heat from stove radiates to warm Fido! Light bulb radiates heat as it creates light!

Radiatio n l A good absorber reflects very little energy – l Think about

Radiatio n l A good absorber reflects very little energy – l Think about dark pavement and/or sand on beach A poor absorber reflects a lot of energy – Think about snow that doesn’t melt in sunshine

HEAT ENERGY HEAT Heat Energy What is HeatHEAT ENERGY HEAT Heat Energy What is Heat
16 Heat Transfer how does heat move Conduction16 Heat Transfer how does heat move Conduction
HEAT TRANSFER CONDUCTION HEAT TRANSFER gjv Recap HeatHEAT TRANSFER CONDUCTION HEAT TRANSFER gjv Recap Heat
Heat Transfer Conduction Convection Radiation Heat Transfer HeatHeat Transfer Conduction Convection Radiation Heat Transfer Heat
Understanding Heat Transfer Heat Transfer Heat always movesUnderstanding Heat Transfer Heat Transfer Heat always moves
Heat Transfer Heat Transfer o o Heat travelsHeat Transfer Heat Transfer o o Heat travels
Heat Transfer Heat Transfer Heat always moves fromHeat Transfer Heat Transfer Heat always moves from
Heat Transfer Heat Transfer Heat always moves fromHeat Transfer Heat Transfer Heat always moves from
Heat Transfer How does the energy move fromHeat Transfer How does the energy move from
HEAT ENERGY AND ITS TRANSFER HEAT TRANSFER BYHEAT ENERGY AND ITS TRANSFER HEAT TRANSFER BY
HEAT TRANSFER Thermal energy transfer is heat movingHEAT TRANSFER Thermal energy transfer is heat moving