1. Day 9 5.3.11 Topic: Finish Convection, Begin Radiation
Obj: I can describe a draw a convection current
Starter: Explain how a
radiator can heat a room.

2. Convection (thru fluid) types
Forced
Fan behind
heat source
Heat Source
Forced
Natural convection
Fluids expand when they heat up. In a container (or environment), warmer fluid floats to the top and cooler fluid sinks to the bottom. This is called natural convection.
Forced convection
In many houses a furnace heats air and then circulates the air to rooms. Since the heat is being forced through the system (with blowers) and circulating with other air, this is another example of convection. However, since the air is forced to flow by the blowers or fans, this is called forced convection.

3. Convection 27 or Conduction 24
Eureka
Convection 27 or
Conduction 24

4. Convection (thru fluid/air)
Land Breeze
DAY OR
EVENING
Sea Breeze

5. Natural Convection Current
Demo:
“Shoe Box
House”
Sketch Either image
1st Floor
2nd Floor
Warm Air
Cool Air
Conclusion:
As warm air rises and exits the house, cool air replaces the warm air which continues the convection current

7. Ball & Ring Demonstration

8. Thermal Radiation
All objects with a temperature above absolute zero (-273 °C or -459 °F) emit thermal radiation. To emit means to give off.
Thermal radiation comes from the thermal energy of atoms.
Thermal radiation is also absorbed by objects. An object constantly receives thermal radiation, otherwise all objects would eventually cool down to absolute zero.
Three identical aluminum bottles were spray painted and set in the window.
Predict the temperature of the fluid inside of each bottle using the oC.
Justify your response.

9. Eureka 29
Thermal
Radiation

10. Radiation: heat transfer in the form of electromagnetic waves, including light.
Sketch this image.
Reflects MOST Radiation
Absorbs MOST Radiation &
Emits as Heat Energy

11. Thermal Radiation
Colors
Black asphalt pavement gets very hot in the summer sun because it effectively absorbs thermal radiation. A silver mirror surface reflects most thermal radiation, while absorbing very little.

12. Solar Radiation
Radiant Energy travels on waves through space on particles or pure energy. Radiation is a heating mechanism that takes place through electromagnetic waves.