HEAT TRANSFER: CONDUCTION

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HEAT TRANSFER CONDUCTION

• DUNMAN SECONDARY SCHOOL
• Science (Physics)

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Some Expectations

• Respect Others
• Respect the School
• Humility

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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!

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Why learn heat transfer?

• Many applications in real life.
• Example Making of engines, refrigerators, air
  cooling systems

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SOLDIER OF TOMORROW

• Soldier suits can regulate temperature!!

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

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Molecular Vibration

• Demonstration of molecular vibration.
• What do you observe about the rate of transfer?
• A slow process

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Test Your Understanding

• Why are gases and liquids generally poor
  conductors of heat?

http//www.cartoonclipart.com/pages/girlread.html
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Insulators and Conductors

• Poor conductors are also called insulators.
• Some examples Water, Wood, Polystyrene.

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Free Electron Transfer

• METALS contain many free electrons.
• See Demostration
• Rate of heat transfer is now faster. Why?

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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.

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Test Your Understanding

• Why is copper a better conductor of heat than
  wood?

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Your research

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

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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

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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