Table of Contents What Is Energy? Forms of Energy Energy Transformations and Conservation Energy and Fossil Fuels

Exponents - What Is Energy? An exponent tells how many times a number is used as a factor. For example, 3 X 3 can be written as 32. You read this number as “three squared.” An exponent of 2 indicates that the number 3 is used as a factor two times. To find the value of a squared number, multiply the number by itself. 32 = 3 X 3 = 9 Practice Problem What is the value of the number 82? 64

Kinetic Energy - What Is Energy? Kinetic energy increases as mass and velocity increases.

Potential Energy - What Is Energy? Gravitational potential energy increases as weight and height increase.

Using Prior Knowledge - What Is Energy? Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about energy in a graphic organizer like the one below. As you read, write what you learn. What You Know The joule is the unit of work. Energy has different forms. What You Learned The two basic kinds of energy are potential energy and kinetic energy.

Click the SciLinks button for links on energy. - What Is Energy? Links on Energy Click the SciLinks button for links on energy.

End of Section: What Is Energy?

Calculating Mechanical Energy - Forms of Energy Calculating Mechanical Energy The kinetic energy of a 500-N diver during a dive from a 10-m platform was measured. These data are shown in the graph.

Calculating Mechanical Energy - Forms of Energy Calculating Mechanical Energy Reading Graphs: According to the graph, how much kinetic energy does the diver have at 8 m? About 1000 J

Calculating Mechanical Energy - Forms of Energy Calculating Mechanical Energy Calculating: Using the graph, find the kinetic energy of the diver at 6 m. Then calculate the diver’s potential energy at that point. Kinetic energy = about 2000 J; potential energy = about 3000 J

Calculating Mechanical Energy - Forms of Energy Calculating Mechanical Energy Inferring: The mechanical energy of the diver is the same at every height. What is the mechanical energy of the diver? About 5000 J

Building Vocabulary - Forms of Energy After you read the section, reread the paragraphs that contain definitions of Key Terms. Use the information you have learned to write a definition of each Key Term in your own words. Key Terms: Examples: nuclear energy electromagnetic energy Key Terms: Examples: mechanical energy A type of potential energy called nuclear energy is stored in the nucleus of an atom. The form of energy associated with the position and motion of an object is called mechanical energy. thermal energy The sunlight that you see each day is a form of electromagnetic energy. The total potential and kinetic energy of the particles in an object is called thermal energy. electrical energy The energy of electric charges is electrical energy. chemical energy Chemical energy is potential energy stored in the chemical bonds that hold chemical compounds together.

Links on Forms of Energy Click the SciLinks button for links on forms of energy.

End of Section: Forms of Energy

Energy Transformations - Energy Transformations and Conservation Energy Transformations Most forms of energy can be transformed into other forms.

Transformations Between Potential and Kinetic Energy - Energy Transformations and Conservation Transformations Between Potential and Kinetic Energy A pendulum continuously transforms energy from kinetic to potential energy and back.

Energy Transformations Activity - Energy Transformations and Conservation Energy Transformations Activity Click the Active Art button to open a browser window and access Active Art about energy transformations.

Asking Questions - Energy Transformations and Conservation Before you read, preview the red headings. In a graphic organizer like the one below, ask a question for each heading. As you read, write answers to your questions. Question Answer What is an energy transformation? An energy transformation is a change from one form of energy to another. What are some examples of transformations between potential and kinetic energy? Juggling and pendulums show transformations between potential and kinetic energy. What is conservation of energy? The law of conservation of energy states that energy cannot be created or destroyed.

End of Section: Energy Transformations and Conservation

Use of Fossil Fuels - Energy and Fossil Fuels Fossil fuels can be burned to release the chemical energy stored millions of years ago.

Previewing Visuals - Energy and Fossil Fuels When you preview, you look ahead at the material to be read. Preview Figure 18. Then write two questions that you have about the diagram in a graphic organizer like the one below. As you read, answer your questions. Using Fossil Fuel Energy Q. What energy transformation occurs in the sun? A. Nuclear energy to thermal energy and electromagnetic energy Q. What energy transformation takes place when coal is burned? A. Chemical energy to thermal energy

Links on Energy Transformations - Energy and Fossil Fuels Links on Energy Transformations Click the SciLinks button for links on energy transformations.

Click the Video button to watch a movie about the use of fossil fuels. - Energy and Fossil Fuels Use of Fossil Fuels Click the Video button to watch a movie about the use of fossil fuels.

End of Section: Energy and Fossil Fuels

Graphic Organizer Energy Kinetic energy Potential energy Joules Work is the ability to do exists as measured in Kinetic energy Potential energy Joules Work which at a given rate is can be Elastic Gravitational Power

End of Section: Graphic Organizer