# Heat Transfer.

## Presentation on theme: "Heat Transfer."— Presentation transcript:

Heat Transfer

Heat transfer Everything is made of molecules.
When molecules gain energy they move faster and create more heat. (The faster the molecules move the hotter they are) Melting Evaporation Condensation Freezing liquid Solid Gas Molecules move very slowly! They are close together. Molecules move faster and are more spread apart. Molecules move very fast! They are very spread apart.

Pair/Share What happens to molecules as you add heat?
Are the molecules of water moving faster or slower in cold water? Why Evaporation is when a Liquid turns into a ____________. Heat is __________. Freezing is when a _________ turns into a ____________. Heat is _____________. If the molecules are moving faster and our more spread out. Was heat added or removed?

Heat Is the transfer of thermal energy from a hotter object to a cooler one until both objects are the same temperature. (You can not transfer cold or give someone cold) heat transfer video clip

Pair/Share Which direction does heat transfer?
A. From warmer to cooler B. From cooler to warmer C. both directions When you touch something cold which direction is heat being transferred? Why? Explain why you feel cold when you touch something that is cold.

3 ways that heat is transferred within the atmosphere

The first method of heat transfer
How does heat energy get from the Sun to the Earth? RADIATION ?

electromagnetic waves?
Radiation What creates electromagnetic waves? Video clip 1 video clip 2 Eureka start at 2:30 The direct transfer of energy by infrared electromagnetic Waves. Sun, fire, light bulbs

Pair Share Partner A: What is radiation and where does it come from.
Partner B: What are three different things that create electromagnetic radiation?

Conduction conduction video clip 1
Eureka The direct transfer of heat from one substance to another substance that is touching. Stepping on hot sand. Ironing Clothes That’s Hot

demo of conduction flame heating molecules

Conduction When you heat a metal strip at one end, the heat travels to the other end. As you heat the metal, the particles vibrate, these vibrations make the adjacent particles vibrate, and so on and so on, the vibrations are passed along the metal and so is the heat. We call this?

Example of Conduction

Pair Share: Partner A: Using the picture on the right explain the conduction process Pair Share: Partner B: Explain how the picture on the left is conducting heat.

Heat video clips\Convection2.asf
convection video clip Heat video clips\Convection2.asf Convection- Eureka The transfer of heat by movement of a fluid (liquids and gases). Cooking peas in water OVEN Dryer Blow Drying your Hair.

Water movement Cools at the surface Convection current Hot water rises
Cooler water sinks

Heating the troposphere
Radiation, conduction and convection work together to heat the troposphere. Radiation- heats the Earth Conduction- Air near earth’s surface is warmed Convection- the warm air molecules rise and transfer heat to the cooler air molecules. Eventually these molecules cool and sink back down to earth. This creates Convection Currents.

Radiation, Convection and Conduction work together to heat the troposphere.
review of all 3 types Radiation Convection Current Conduction

Review Heat transfer from a hotter object to a cooler object until both objects are the same temperature. 3 types of heat transfer Radiation – electromagnetic waves Conduction – touching Convection- through a fluid (liquid or gas) All 3 work together to heat the troposphere but Convection causes most of the heating.

Review Heat transfer from a hotter object to a cooler object until both objects are the same temperature. 3 types of heat transfer review, review 2 Music Review Radiation – electromagnetic waves Conduction – touching Convection- through a fluid (liquid or gas) All 3 work together to heat the troposphere but Convection causes most of the heating.

Radiation, Convection and Conduction work together to heat the troposphere.