1. Section 10.2 Energy Transfer

2. Methods of Energy Transfer There are 3 methods of energy transfer. Conduction Conduction Convection Convection Radiation Radiation

3. Conduction When objects are in contact and there is transfer of heat energy. When objects are in contact and there is transfer of heat energy.

4. Convection This results from the movement of warm fluids (liquids or gas) This results from the movement of warm fluids (liquids or gas) The cycle of a heated fluid that rises and then cools and falls is called convective current. The cycle of a heated fluid that rises and then cools and falls is called convective current.

5. Convection current The cycle in which the flow of the fluid is due to heated expansion followed by cooling and contraction. The cycle in which the flow of the fluid is due to heated expansion followed by cooling and contraction.

6. Radiation Radiation does not require physical contact between objects. Radiation does not require physical contact between objects. Electromagnetic waves include: infrared radiation, visible light and ultraviolet rays. Electromagnetic waves include: infrared radiation, visible light and ultraviolet rays.

7. Radiation Radiation is different from conduction and convection because it does not involve the movement of matter. Radiation is different from conduction and convection because it does not involve the movement of matter. Radiation is the only method of energy transfer that can take place in a vacuum, ex. outer space. Radiation is the only method of energy transfer that can take place in a vacuum, ex. outer space.

8. Conductors and Insulators Energy is transferred as heat quickly in conductors. Conductor: Def. p.334. Conductor: Def. p.334. Metals are good conductors of heat because energy passes through it easily and quickly. Metals are good conductors of heat because energy passes through it easily and quickly.

9. Non metals are not good conductors. Non metals are not good conductors. The state of matter (solid, liquid or gas) determines if it is a good conductor too. The state of matter (solid, liquid or gas) determines if it is a good conductor too.

10. Insulators Insulators slow the transfer of energy as heat. Poor conductors of heat and electricity Poor conductors of heat and electricity We use insulators to stop or reduce unwanted energy transfer, ex. wooden spoon. We use insulators to stop or reduce unwanted energy transfer, ex. wooden spoon.

11. Specific Heat energy in Joules required to raise an object’s temperature by 1 Kelvin. energy in Joules required to raise an object’s temperature by 1 Kelvin. Symbolized by the letter c Symbolized by the letter c Specific heat is a physical property. Specific heat is a physical property. The unit for Specific heat is J/kg.K The unit for Specific heat is J/kg.K Specific heat equation p.337. Specific heat equation p.337.