1. ENERGY

2. What is Energy? Energy is the ability to do Work.
Energy is measured in joules or J

3. Practical examples One joule approximately equals:
The energy required to lift a small apple one meter straight up.
The energy released when that same apple falls one meter to the ground.
The energy released as heat by a person at rest, every hundredth of a second.
The energy of a tennis ball moving at 23 km/h (14 mph).
Do you know how many joules are in a 100g bar of chocolate?
1 Million Joules !!

4. Principle of the Conservation of Energy
Energy cannot be created or destroyed only changed from one form into another.

5. The 9 forms of Energy Kinetic Nuclear Potential Chemical Light
Heat
Sound
Nuclear
Chemical
Magnetic
Electrical

7. Review of the types of Energy
Kinetic: Energy stored in a moving body e.g. runners or a moving car.
Potential: This is stored energy just waiting to do work e.g. a coiled spring, stretched elastic or an apple held above the ground.
Chemical: Energy stored inside materials in the chemical bonds e.g. food or fossil fuels.
Sound: Stores energy and cause the air to vibrate/move e.g. radio or a whistle.

8. Electrical: Energy due to moving charges; used by household appliances to move things.
Heat: Heat can also move things e.g. alcohol in a thermometer and the pistons in an engine.
Nuclear: this is energy stored in the centre (nuclei) of atoms.
Light: One of the most important forms of energy, gives energy to plants to grow.
Magnetic: magnets have the ability to move things e.g. the needle of a compass or a bar magnet attracting paperclips.

10. Experiment to Show Converting Chemical energy to Electrical energy to Heat energy

11. Apparatus
Thermometer, 6V battery, wire, cables, crocidile clips, stand

12. Method Set up apparatus as shown in the diagram.
Record the temperature of the wire.
Close the switch.
Observe the thermometer and record the temperature of the wire after 1 minute.
Open the switch.
Record the temperature of the wire after 1 minute.

13. Result
The thermometer shows an increase in temperature in the wire while the switch is closed. The temperature decreases when the switch is opened again.

14. Conclusion
Some of the chemical energy in the battery has been converted into electrical energy in the wires. Some of this electrical energy in the wires has then been converted into heat energy and this was detected by the thermometer.