1. Thermal Energy & Heat Transfer
Advanced Physical Science
Lockwood

2. Kinetic Energy Energy of Motion KE = ½ m* V2
When you were acting as a particle…the more you jumped around…the more KE you had
All matter contains particles that are moving all the time
Absolute zero=when matter stops moving (never been reached)

3. Temperature
Temperature is the measure of the average kinetic energy of the particles in an object.
The gas particles on the right have a higher KE than those on the left (therefore higher temperature)

4. Temperature (con’t)
Temperature does not depend on how much substance you have
The contents of the teapot and the coffee cup are at the same temperature

5. Thermal Energy
The TOTAL KE of all the particles that make up the object
The higher the temperature, the higher the thermal energy
The more substance present, the greater the thermal energy (there is more thermal energy in the pan of soup than the bowl)

6. Heat
The energy transferred between objects that are at different temperatures (diff Ave KE).
Energy is transferred from faster (warmer) molecules to slower (cooler) molecules
Occurs through collisions between molecules
HEAT MOVES!! (not cold)
Heat is what causes something to FEEL hot or cold
Ex: A doctor’s stethoscope on your back…your body heat is moving to the stethoscope.

7. Heat Transfer-3 types
Conduction
Convection
Radiation

8. Heat Transfer - Conduction
Conduction- transfer of energy through matter by the direct contact of particles
When objects that have different temperatures come into contact, energy passes from warmer to cooler object until both have same temperature.
Occurs because particles are in constant motion
KE transferred as particles collide

9. Heat Transfer – Conduction (cont)
Conduction can also occur within an object such as the spoon (below). The part of the spoon in the soup is hotter than the edge.
Conduction works best in solids- especially metals- because particles are close together
Metals- good conductors-because electrons move easily & transfer KE to nearby particles

10. Heat Transfer - Convection
Convection- transfer of thermal energy by the movement (or circulation) of a fluid
Fluid- any material that flows (can be liquid or gas)
Convection currents transfer heat from warmer to cooler parts of a fluid.

11. Conduction and Convection
Convection vs. Conduction-
Conduction involves collisions and transfers of energy.
Convection involves movement of the energetic particles from one location to another
Conduction and convection can occur only when matter is present.

12. Heat Transfer - Radiation
Radiation is heat transfer through space as electromagnetic waves.
Does not require a medium.

13. Heat Transfer-summary of all types
Conduction, Convection, and Radiation can occur in the same situation