2. Energy

3. Potential Energy –Ex: A rock on top of a cliff has potential energy because of its position above ground level –Ex: A lump of coal contains potential energy in its chemical bonds, causing fire when exposed to a flame

4. Kinetic Energy –Ex: A rock falling off a cliff –The heat given off by a burning lump of coal –The faster an object moves, the more kinetic energy it has

5. Energy –Ex: Water held back by a dam has potential energy but no kinetic energy. Releasing the water and letting it flow changes its potential energy into kinetic energy.

6. Energy –Ex: When a ball is thrown straight up in the air, its kinetic energy changes into potential energy as the ball rises higher above the ground. At the highest point, the ball is motionless and has only potential energy. As the ball falls back to the ground, the potential energy changes back into kinetic energy.

7. Forms of Energy  There are 6 forms of energy

8. Mechanical Energy –Ex: hammer striking a nail, a jack lifting a car, pedals turning the wheel of a bike –Sound is a type of mechanical energy

9. Chemical energy –Ex: coal, oil, natural gas, food

10. Nuclear energy –Joining small nuclei together or splitting large nuclei apart

11. Heat Energy –Ex: rubbing your hands together, cellular respiration, burning fuel oil in a home

12. Electric Energy –Ex: computers, light bulbs, washing machines all are operated with electric energy. –A generator produces electric energy.

13. Light Energy –Ex: magnifying glass burns a hole in a leaf or using a laser beam to burn a hole in a steel plate.

14. Conservation of Energy  Energy can easily be transformed from one type of energy into another type of energy

15. Conservation of Matter  Energy and matter are interchangeable. The total amount of energy and matter in the universe is constant and each can be converted into the other. –Ex: The sun converts large amounts of matter into light and heat energy

16. Energy Transformations  Ex: when you take a bus to school, ______ energy in the gas is changed into __________ energy that turns the wheels of the bus  Ex: The bell rings between classes, ______ energy is transformed into ______ energy  Ex: At night when you are reading, _______ energy is changed into _____ energy

17. Unusable Energy  During energy transformation heat energy is produced that is not usable. –A cars motor changes chemical energy in gas into mechanical energy to move the car. The motor eventually becomes hot due to the burning of fuel and friction of the motors moving parts rubbing against one another

18. Unusable Energy  Ex: a vacuum cleaner contains a motor that transforms electric energy into mechanical energy. Run a vacuum cleaner for a few minutes and it gets warm. The electric energy entering the motor produced mechanical energy to operate the appliance and an unusable amount of heat energy.