Topic 6

1. Topic 6 Transferring Energy

2. Define • Energy Source: an object or material that can transfer its energy to other objects • Conduction: is the process of transferring (thermal) energy through direct collisions between particles • Convection: the rise of warmer materials and the sinking of cooler materials • Tsunami: an underwater earthquake • Thermal conduction: same as conduction* • Heat Insulator: (poor conductors) slow down the transfer of thermal energy to or from the surroundings • Radiation is the transfer of energy without any movement of matter

3. 3 ways in which energy can be transferred pg.226 • Radiation • Conduction • Convection

5. Thermal energy is transferred from the heat source in the form of a wave

6. The wave can travel through materials, and even through empty space

7. Radiation Transfers Energy • Give a synonym of radiant energy: Electromagnetic radiation (EMR) • How does radiant energy travel through space? Like a wave

8. The Different forms of EMR pg.226 • Radio waves • Microwaves • Visible light • X-rays

9. How does an X-Ray work? • http://www.youtube.com/watch?v=wbbsbE2mQuA

11. How do Microwaves work? • http://www.youtube.com/watch?v=Jwxm-9X7DZE

12. 3 Characteristics shared by the different forms of radiant energy • They behave like waves • They can be absorbed and reflected by objects • They travel across empty space at the same very high speed: 300 000 km/s

13. Pg. 229 • In solids, where particles are close together, thermalenergy can be transferred directly from one particle to the other. Thermal conduction is the process of transferring thermalenergy through direct collisions between particles

14. Excellent heat conductors • Gold • Copper

15. Poor Heat Conductors • Glass • Wood

16. Synonym of “poor conductor” • Heat Insulators

17. Sea and land breezes are convection currents that occur in nature. Warmer air rises and cooler air moves in to take its place a) During the day, the land heats up faster than the sea. The warmer air above the land rises. This allows the cool sea air to move in, causing a sea breeze. Diagram:

18. Convection, Energy on the Move • Thermal energy can be transferred in a third way by convection; liquids and gases. In convection, the warm fluid moves producing a convection current (moving fluid)

19. Why do fluids at different temperatures rise? • Materials expand or move farther apart when warmed in which fewer particles become lighter. (warmed material becomes less dense) As warm fluid rises and moves away from the heat source, it cools. It contracts as its particles move closer together.

20. What creates a convection current? • The warming and cooling of particles. It changes the density. The warm particles rise and cool particles sink.

21. Features of Energy Transfer Systems • Energy Source • Direction of Energy Transfer • Transformations- ex. In the air, on the floor, sound • Waste Heat • Control Systems

22. b) During the night, the land cools faster than the sea. The warmer air above the sea rises. The cooler air over the land moves in to take its place, creating a land breeze. Diagram:

23. Under what conditions would no breezes occur? • If the sea and land were the same temperature, there would not be any hot air rising, therefore not allowing convection to happen.

24. Insulation & RSI Values RSI= RSI/cm X Thickness

25. Which is a better insulator, plywood or glass, if the same thickness of material is used? How do you know?