1. Heat energy Unit2 Lesson 3 Transfer of heat energy.

2. 1.How do we know that heat is tranferred? 2.What is conduction? 3.What is convection? 4.What is radiation? Key Questions November 2009MPW/EQI slide 2

3. 1.How do we know that heat is tranferred? The handle of the metal spoon in hot water becomes warm. The heat is tranferred from the hot water to the handle of the spoon. Starter November 2009MPW/EQI slide 3

4. 2.What is conduction? Conduction is the transfer of heat energy through a solid material. Key Questions November 2009MPW/EQI slide 4

5. 3.What is convection? Convection is the tranfer of heat energy by a hot liquid or gas as it flows. Key Questions November 2009MPW/EQI slide 5

6. Explain why this ice cube does not melt. Use your knowledge of convection. The warm water is lighter and will not go down to the bottom to melt the ice cube. Demonstration convection November 2009MPW/EQI slide 6

7. 4.What is radiation? Radiation is the tranfer of heat energy in the form of infra-red radiation. Key Questions November 2009MPW/EQI slide 7

8. November 2009MPW/EQI slide 8 conductors and insulators in the kitchen

9. slide 9 ItemWhat it is made of How it helps or prevents heat flow Conductor or insulator? kettle element (heater) steelAllows heat to flow to the water. conductor kettle handleplasticstops heat flow from kettle to hand insulator base of the iron metalallows heat to flow from hot iron to clothes conductor cover of the ironing board padded fabric stops heat from from clothes to ironing board insulator panmetalallows heat to flow from fire to food conductor stirrerwoodstops heat from flowing from hot pan to hand insulator table matscorkstops heat from flowing from hot plate to table insulator

10. Summary November 2009MPW/EQI slide 10 http://earthfortress.com/wp-content/uploads/2009/06/heatrans.jpg