1. HEAT TRANSFER: CONDUCTION
DUNMAN SECONDARY SCHOOL
Science (Physics)

2. Some Expectations
Respect Others
Respect the School
Humility

3. Work Ethic
DO participate and ask questions. For order in class, raise your hand when asking a question.
BRING all specified books.
HAND IN all homework ON TIME! Failure to do so may result in consequences… (“Drink coffee” with Mr. Chew after school)
SHOW CARE and concern for each other. Help one another in homework. BUT NO COPYING OF ENTIRE ASSIGNMENTS!

4. Why learn heat transfer?
Many applications in real life.
Example: Making of engines, refrigerators, air cooling systems…

5. SOLDIER OF TOMORROW
Soldier suits can regulate temperature!!

7. CHALLENGE!!
How do you place a piece of paper over a candle flame without the paper catching fire?

8. CONDUCTION
Conduction is the transfer of thermal energy without any flow of the material medium.
This is the main process by which thermal energy is transferred from one of the solid to another.

9. Free Electron Diffusion
Molecular Vibration
CONDUCTION
can occur by

10. Molecular Vibration Demonstration of molecular vibration.
What do you observe about the rate of transfer?
A slow process…

11. Test Your Understanding
Why are gases and liquids generally poor conductors of heat?

12. Insulators and Conductors
Poor conductors are also called insulators.
Some examples: Water, Wood, Polystyrene.

13. Free Electron Transfer
METALS contain many free electrons.
See Demostration
Rate of heat transfer is now faster. Why?

14. Free Electron Diffusion
When heated, the free electrons move faster and diffuse to into the cooler parts of the metal.
Kinetic energy is then transferred to the molecules by collision.

15. Test Your Understanding
Why is copper a better conductor of heat than wood?

16. Your research What are some applications of:
Conductors
Insulators
in everyday life? (Choose one)
Do in groups of two or three.

17. Your Research Presentation format – YOU DECIDE
Concept Maps with Pictures?
Short video? (Takes a long time… but if you can… why not?)
Research Paper?? (you sure???)
The point is: BE INNOVATIVE
Dateline: 20 Mar 2006 (Mon) 1300 hrs

18. What we have learnt…
The main process by which thermal energy is transferred from one end of a solid to another is conduction.
Two mechanisms of conduction:
Molecular vibration
Free electron diffusion
Done by: Chew Yiming Clement