1. Sci. 5-3 Conservation of Energy Pages 131-133

2. A. Friction- a force that opposes motion between two surfaces that are touching.

3. B.Because of friction, some energy is always converted into thermal energy during a energy conversion.

4. C. Closed System- a well- defined group of objects that transfer energy between one another.

5. D. Energy is conserved within a closed system. Energy is converted into other forms of energy.

6. E. The Law of Conservation of Energy-energy can be neither created nor destroyed. The total AMOUNT of energy in a closed system is always the same.

7. F. Anytime one form of energy is converted into another form, some of the original energy is ALWAYS gets converted into thermal energy. (HEAT)

8. G. Perpetual Motion Machine- a machine that runs forever without any additional energy input. This machine would put out as much energy as was put in. Not Really

9. H. Perpetual motion is IMPOSSIBLE because some of the energy put into the machine will eventually be converted completely into thermal energy due to friction. This thermal energy is waste energy.