1. Energy Conversion - a change from one form of energy to another Some energy is always wasted (converted into thermal energy)

2. break down energy from food; use it to be active and to maintain constant body temperature photosynthesis

3. batteries light bulb microphone toaster

4. Machines  Machines… Machines DO NOT… can make work easier by changing the size and/or direction of the force required to do the work transfer and convert energy. increase energy.

5. Examples: bicycle hammer nutcracker

6. Law of Conservation of Energy  energy cannot be created or destroyed Energy is just transformed (converted) from one form to another. All of the energy put into a process still exists somewhere. Some energy is always converted into thermal energy.  NO machine has perpetual motion – they all need a constant supply of energy

7. Energy Efficiency - compares the amount of energy before a conversion with the amount of useful energy after the conversion

8. Which light bulb is more energy efficient?