1. Chapter 4
Energy

2. What is Energy? When you think of energy, what comes to mind??
Energy is the ability to cause change.

3. Different Forms of Energy
Four forms of energy:
Electrical
Chemical
Radiant
Thermal

4. Nature’s Money
If you have $100, you could store it in a variety of forms
Cash
Bank Account
Traveler’s checks
Gold or silver coins
Regardless of how you transfer your money, it is still money.

5. Kinetic Energy
The word "kinetic" is derived from the Greek word meaning to move, and the word "energy" is the ability to move. Thus, "kinetic energy" is the energy of motion --it's ability to do work.
The greater the mass and speed of an object the more kinetic energy there will be.
Example: As the train accelerates down the hill the potential energy is converted into kinetic energy. There is very little potential energy at the bottom of the hill, but there is a great amount of kinetic energy.

6. Kinetic Energy= ½ mass x speed
KE= ½ mv2
example: turn to page 102

7. Potential Energy
“Stored” energy
A hanging apple from an apple tree

8. Types of Potential Energy
Elastic Potential Energy
Energy stored by something that can stretch of compress (rubber band, spring)
Chemical Potential Energy
Energy stored in chemical bonds
Gravitational Potential Energy
Energy stored by objects due to their positive above Earth’s surface

9. Gravitational Potenial Energy
GPE= mass x acceleration of gravity x height
GPE= mgh