1. Chapter 13
Section 1 – ENERGY!

2. What is energy? 1
The Nature of Energy
When an object has energy, it can make things happen.
Energy is the ability to cause change.

3. What is energy? 1
Transferring Energy
Everything around you has energy, but you notice it only when a change takes place.
Anytime a change occurs, energy is transferred from one object to another.
For example, leaves are put into motion when energy in the moving wind is transferred to them.

4. Energy of Motion 1 Things that move can cause change.
What is energy? 1
Energy of Motion
Things that move can cause change.
Kinetic energy is the energy an object has due to its motion.
If an object isn’t moving, it doesn’t have kinetic energy.

5. Kinetic Energy and Speed
What is energy? 1
Kinetic Energy and Speed
If you roll a bowling ball so it moves faster, what happens when it hits the pins?
A faster ball causes more change to occur than a ball that is moving slowly.
The faster the ball goes, the more kinetic energy it has. This is true for all moving objects.

6. Kinetic Energy and Mass
What is energy? 1
Kinetic Energy and Mass
Suppose you roll a volleyball down the alley instead of a bowling ball.
The volleyball might not knock down any pins.

7. Kinetic Energy and Mass
What is energy? 1
Kinetic Energy and Mass
An important difference between the volleyball and the bowling ball is that the volleyball has less mass.
Even though the volleyball is moving at the same speed as the bowling ball, the volleyball has less kinetic energy because it has less mass.
Kinetic energy also depends on the mass of a moving object. Kinetic energy increases as the mass of the object increases.

8. What is energy? 1
Energy of Position
An object can have energy even though it is not moving.
Potential energy is the energy stored in an object because of its position.

9. What is energy? 1
Energy of Position
The potential energy of an object is greater if it is higher above the floor.
Potential energy also depends on mass. The more mass an object has, the more potential energy it has.

10. Forms of Energy—Thermal Energy
What is energy? 1
Forms of Energy—Thermal Energy
All objects have thermal energy that increases as its temperature increases.
A cup of hot chocolate has more thermal energy than a cup of cold water.
Many chemical reactions that take place inside your cells produce thermal energy.
Thermal energy released by chemical reactions comes from another form of energy called chemical energy.

11. What is energy? 1
Chemical Energy
Chemical energy is the energy stored in chemical bonds.
When chemicals are broken apart and new chemicals are formed, some of this energy is released.
The flame of a candle is the result of chemical energy stored in the wax.

12. What is energy? 1
Light Energy
When the light is absorbed by an object, the object can become warmer.
The object absorbs energy from the light and this energy is transformed into thermal energy.
The energy carried by light is called radiant energy.

13. What is energy? 1
Electrical Energy
The electric current that comes out of batteries and wall sockets carries electrical energy.
The amount of electrical energy depends on the voltage.
To produce the enormous quantities of electrical energy consumed each day, large power plants are needed.

14. What is energy? 1
Nuclear Energy
Nuclear power plants use the energy stored in the nucleus of an atom to generate electricity.
Every atomic nucleus contains energy—nuclear energy—that can be transformed into other forms of energy.

15. Question 1 1 Energy is the ability to cause _______. A. change
Section Check 1
Question 1
Energy is the ability to cause _______.
A. change
B. chemical energy
C. kinetic energy
D. potential energy

16. Section Check 1
Answer
The answer is A. An object that has energy can do something or make something happen.

17. Section Check 1
Question 2
Whenever a change occurs _______ is transferred from one place to another.
A. electricity
B. energy
C. motion
D. waves

18. Section Check 1
Answer
The answer is B. Clap your hands; energy has been transferred from your hands through the air to your ear.

19. Section Check 1
Question 3
The energy an object has due to its motion is called _______ energy.
A. chemical
B. electrical
C. kinetic
D. potential

20. Section Check 1
Answer
The answer is C. Anything that is moving, from a rocket to a falling leaf, has kinetic energy.