1. Heat Transfer Conduction, Convection, & Radiation…oh my!!

2. Energy can be transferred in 3 ways… 1. Conduction 2. Convection 3. Radiation

3. Conduction Conduction: the transfer of energy through direct contact of a material –occurs within a material or between materials that are touching

4. What phase of matter do you think conduction travels best in? SLOWER in gases is than in liquids and solids because the particles collide less often in a gas Conduction occurs fastest in SOLIDS!!!

5. Thermal conductor: transfer of heat energy through a material a) Examples: -Wire rack in hot oven - Tile floor Thermal Insulator: material that is a poor conductor of heat and therefore reduces energy transfer Thermal Insulator: material that is a poor conductor of heat and therefore reduces energy transfer a) Examples: -Wooden spoon - Air - Styrofoam Materials can be Conductors or Insulators:

6. Convection: the movement of matter due to different temperatures densities! Convection: the movement of matter due to different temperatures having different densities! Convection

7. Convection causes currents! Energy flows from HIGH to LOW (hot to cold) Energy flows from HIGH to LOW (hot to cold) Example: Oven Example: Oven –Temp is higher at bottom of the oven – Air at bottom heats up & is then less dense HOT air RISES –The air that was at the top, cools off & is then more dense COLD air SINKS

8. Convection current: the vertical movement of air currents due to temperature variation Convection currents are important in many natural cycles, such as ocean currents, weather systems, and movements of hot rock in Earth’s interior.

9. Radiation: the energy that is transferred as electromagnetic waves, such as visible light & infrared waves Travel: Requires NO medium!! Examples: - Sun - Standing by grill & feel the heat - Heat lamp in restaurant Radiation

10. Heat Transfer Recap!