1. Energy Transfer Mrs. Wolfe

2. How do things transfer energy? Why does a spoon get warm when you put it in hot chocolate? Why does a spoon get warm when you put it in hot chocolate? What’s happening at the ATOMIC level? What’s happening at the ATOMIC level?

3. Conduction Vibrating atoms bump into each other. Vibrating atoms bump into each other. This is called conduction. This is called conduction. Objects in direct contact. Objects in direct contact. Works best in solids. WHY? Works best in solids. WHY? VIDEO! VIDEO!

4. Materials CONDUCT at different rates DEMO!! DEMO!! Conductometer Conductometer

5. The Amazing Ice Melting Blocks

6. How can I prove that energy is being transferred? DEMO - What happens to the atoms in this ball when I heat it? DEMO - What happens to the atoms in this ball when I heat it? As a result, it should expand, right? As a result, it should expand, right?

7. Energy Transfer Conduction is not the only way of transferring energy! Conduction is not the only way of transferring energy! 3 ways to transfer energy: 3 ways to transfer energy: Conduction Conduction Convection Convection Radiation Radiation

8. Convection MOVEMENT due to DENSITY MOVEMENT due to DENSITY Temperature changes CAUSE density changes. Temperature changes CAUSE density changes. Examples: Examples: Look over a campfire at a friend. The swirls above the fire are hot air rising. Look over a campfire at a friend. The swirls above the fire are hot air rising. Mostly gases & liquids; WHY? Mostly gases & liquids; WHY?

11. DEMOS Genie in a Bottle Genie in a Bottle Smoking Chimney Smoking Chimney Making Mac ‘n’ Cheese Making Mac ‘n’ Cheese

12. Why is the furnace in the BASEMENT of a house? Why is the furnace in the BASEMENT of a house? Why do we put air vents on the floors of houses in Ohio? Why do we put air vents on the floors of houses in Ohio? Where should they be in Florida? Where should they be in Florida? Practice Problems

14. Radiation Involves LIGHT!! Involves LIGHT!! Does NOT need matter!! Does NOT need matter!! Examples: Examples: Sunlight travels thru space. Sunlight travels thru space. REFLECTION! REFLECTION!

15. REVIEW Conduction – solids; direct contact Conduction – solids; direct contact Convection – gases/liquids; density Convection – gases/liquids; density Radiation – through a vacuum Radiation – through a vacuum

17. Time for a LAB!!

18. Practice Problem Predict whether the hottest part of a room will be near the ceiling, in the center, or near the floor. Predict whether the hottest part of a room will be near the ceiling, in the center, or near the floor. What method of energy transfer tells you this? What method of energy transfer tells you this?

19. Explain why cookies baked touching the turned-up edges of a cookie sheet brown more than those baked near the center. Explain why cookies baked touching the turned-up edges of a cookie sheet brown more than those baked near the center. Practice Problem

20. DEMO – The flame-resistant paper cup DEMO – The flame-resistant paper cup DEMO – The flame-resistant index card DEMO – The flame-resistant index card WHY??? WHY??? Practice Problem