1. How is heat energy transferred?

2. There are 3 methods of heat transfer:
Conduction
Convection
Radiation

3. What’s that supposed to mean?
Huh?
What’s that supposed to mean?
Conduction
The transfer of energy through molecular contact.
Think of a train.
A train only haas one car pulling it but the whole train moves. If you took off the last 2 cars of the train, would they move?

4. How conduction works.
Just like in a train, each molecule gets its energy from the molecules before it. If you separate the molecules then the energy cannot be transferred.
Which phase of matter would this work best in?
Solids
Why?
The molecules are close together.

5. Conduction in non-metals

6. Conduction in metals
Conduction in metals

7. Conduction
Conduction

8. Conduction experiment
Which candle will fall first?
Why did they fall in that order?
The heat only heated up one end of the bar but then the heat was conducted to the rest of the bar melting the wax as it heated up.

9. Why do you think the woman in the pink coat dropped her stick while the one in the blue one didn’t?
Her stick was made of metal. Metals have their molecules packed close together so they make good conductors.
The candle heats one end and then the heat travels down the length of the bar, from one molecule to the next. It’s the reason why you don’t immediately burn yourself when you first put metal into a fire.

10. What do these pictures have in common?
These are examples of insulators. Insulators do not allow heat to travel through them. They keep the heat in.

11. ConVection Transfer of heat through fluids (liquids and gases)
Results from differences in density within the fluids
Ex: warm air rises, cool air sinks
Creates a CONVECTION CELL

12. Convection in Liquids
Convection in Liquids

13. Convection within a liquid

14. The liquid by the heat becomes less dense and rises and then sinks again as it becomes more dense.

15. How convection works.
Away from the heat the heated air cools and becomes more dense.
Heated, less dense air rises.
The cooler, more dense air sinks back to the ground.
The cooler air moves in to take the place of the heated air that has risen and so it also becomes heated causing the cycle to repeat.

16. Convection in Gases
Convection in Gases

17. Pictorial examples of convection in a gas.

18. Convection is the reason why we have cool lava lamps!

19. Convection
Convection

20. Radiation is the transfer of energy through empty space.
All objects radiate energy (unless at absolute zero). This is when molecules stop moving completely. Since this never happens this temperature is only theoretical.
Radiation is the transfer of energy through empty space.

21. Radiation
Radiation

22. Radiation
Radiation

23. Emitting Radiation
Emitting Radiation

24. Absorption of Radiation

25. Absorbing & Emitting Radiation

26. Three methods of energy transfer.
The person also feels the heat in the handle through the process of conduction.
The water touching the pot is heated through conduction but the heat is then transferred throughout the rest of the pot through convection.
The fire radiates energy through empty space providing heat to the pot.

27. Which method of energy transfer is responsible for making the popcorn?
Jiffy pop is conduction
Radiation
Air popper is convection

28. Quiz
Quiz

29. Wordsearch
Wordsearch