Energy

1. Efficiency

1.1. A measure of how good a device is at changing energy into a useful form

1.2. Always less than one

2. Forms of energy

2.1. Heat energy

2.2. Light energy

2.3. Sound energy

2.4. Chemical energy

2.4.1. Food, fuel and batteries

2.5. Nuclear energy

2.5.1. Bombs, stars and radioactive materials

2.6. Kinetic energy

2.6.1. Moving objects

2.7. Electrical energy

2.8. Gravitational potential energy

2.8.1. The higher you lift an object the more GPE it gains

2.9. Elastic potential energy

2.9.1. Energy stored in an elastic material when it is stretched

3. Law of consevation of energy

3.1. Energy cannot be created

3.2. Energy cannot be destroyed

3.3. Energy can be changed from one form into another form

4. Devices

4.1. Useful and wasted

4.1.1. Always ends up as heat energy and spreads out into the surroundings

4.1.1.1. Useful

4.1.1.1.1. Energy from a device in a form that we need

4.1.1.2. Wasted

4.1.1.2.1. Energy from a device in a form that we do not need (usually heat)

4.2. Sankey diagrams

4.2.1. New node