1. Energy 3.1 Energy exists in different forms. 3.2
the BIG idea
Energy
CHAPTER
Energy has different forms, but it is always conserved.
3.1
Energy exists in different forms.
3.2
Energy can change forms but is never lost.
CHAPTER OUTLINE

2. Energy exists in different forms.
3.1
Energy exists in different forms.
• Energy is the ability to cause a change.
• Different forms of energy produce changes in different ways.
energy
kinetic energy
• Kinetic energy depends on mass and speed.
potential energy
High Speed
Low Speed
SECTION
OUTLINE

3. Energy exists in different forms.
3.1
Energy exists in different forms.
• Energy is the ability to cause a change.
• Different forms of energy produce changes in different ways.
energy
kinetic energy
• Kinetic energy depends on mass and speed.
potential energy
• Potential energy depends on position and chemical composition.
SECTION
OUTLINE

4. 3.1 energy Energy exists in different forms.
kinetic energy
The ability to do work or to cause a change. For example, the energy of a moving bowling ball knocks over pins; energy from food allows animals to move and to grow; and energy from the Sun heats Earth’s surface and atmosphere, which causes air to move.
potential energy
KEY CONCEPT
SUMMARY

5. 3.1 kinetic energy Energy exists in different forms.
The energy of motion. A moving object has the most kinetic energy at the point where it moves the fastest.
potential energy
KEY CONCEPT
SUMMARY

6. 3.1 potential energy Energy exists in different forms.
kinetic energy
Stored energy; the energy an object has due to its position, molecular arrangement, or chemical composition.
potential energy
KEY CONCEPT
SUMMARY

7. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
• Energy often needs to be transformed in order to produce a useful form of energy.
law of conservation of energy
• The law of conservation of energy states that energy is never created or destroyed.
energy efficiency
SECTION
OUTLINE

8. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
• Energy often needs to be transformed in order to produce a useful form of energy.
law of conservation of energy
• The law of conservation of energy states that energy is never created or destroyed.
energy efficiency
• Energy can be transformed in many different ways, including from potential energy (PE) to kinetic energy (KE) and back again. PE PE KE PE KE
SECTION
OUTLINE

9. law of conservation of energy
3.2
Energy can change forms but is never lost.
law of conservation of energy
law of conservation of energy
energy efficiency
A law stating that no matter how energy is transferred or transformed, it continues to exist in one form or another.
KEY CONCEPT
SUMMARY

10. 3.2 energy efficiency Energy can change forms but is never lost.
law of conservation of energy
energy efficiency
energy efficiency
A measurement of usable energy after an energy conversion; the ratio of usable energy to the total energy after an energy conversion.
KEY CONCEPT
SUMMARY

11. 3.1 Energy exists in different forms.
I. Energy exists in different forms.
energy
A. Different forms of energy have different uses.
kinetic energy
1. Energy
potential energy
2. Forms of Energy
B. Kinetic energy and potential energy are the two general types of energy.
1. Kinetic Energy
2. Potential Energy
KEY CONCEPT
SUMMARY

12. Energy can change forms but is never lost.
3.2
Energy can change forms but is never lost.
II. Energy can change forms but is never lost.
law of conservation of energy
A. Energy changes forms.
1. Conversions Between Potential Energy and Kinetic Energy
energy efficiency
2. Using Energy Conversions
B. Energy is always conserved.
C. Energy conversions may produce unwanted forms of energy.
KEY CONCEPT
SUMMARY