Energy and Change.
作者：Isabella Sangweni
1. Conduction.
1.1. Materials, such as plastics and wood, slow down or prevent conduction. They are called insulators.
1.2. Materials, such as metals, conduct heat well. They are called conductors of heat.
2. Convection
3. Radiation
4. Transfer of energy between soild objects by touching each other. touching a hot stove
5. Transfer of energy in liquids and gases that move. Boiling water
6. Transfer of energy where objects do not have to be physically touching. Sun heat to earth
7. Heat insulation and energy saving
8. Minimised or prevented to reduce:
9. Heat: EnerEnergy
10. Through the Law of Conservation of Energy.
10.1. Energy cannot be created or destroyed.
10.2. It can only be transferred from one part of a system to another
11. Electrical
12. Useful and wasted energy
12.1. Energy that is in a system is called output energy.
12.2. Energy that is transfered in a systm is used to provide a useful output energy
13. Energy
13.1. The ability of doing work.
13.2. For example cooking,lifting objects.
14. Thermal
15. Forms of sources.
15.1. Renewable sources are ones which can be recycled or reused.
15.2. Examples of renewable sources wind,sun
15.3. Non- Renwable sources are sources that can not be recycled and reused and so there is a limited amount available and when that runs out there will be none left.
15.4. Examples: Oil, Gas and Coal.
16. Potential and Kinetic energy
16.1. Potential energy is energy that a body or system has that is stored.
16.2. Examples: a rock on top of the hill.
16.3. Kinetic energy is energy that a or body or sysytem because of movement.
16.4. Examples: a car moving
17. Systems
18. Mechanial
19. Biological
20. Insulating materials
20.1. to improve energy effciency
20.2. in indigenous homes and technologies , appliances and buildings
21. Heat loss
21.1. like electric geysers
22. like cool boxes
23. energy transfer
24. some energy is wasted or lost through :
24.1. light
24.1.1. Light bulbs and other light sources convert electrical or chemical energy into light energy, but some of that input energy is also converted into heat.
24.2. heat
24.2.1. When a car engine runs, some energy is used to move the car, but a lot of it is wasted as heat because the engine becomes very hot.
24.3. sound
24.3.1. A hairdryer makes a loud noise while drying your hair, and that sound is not useful it’s wasted energ.