Page 84 - 9780077418427.pdf
P. 84
/Users/user-f465/Desktop
tiL12214_ch03_061-084.indd Page Sec3:61 9/3/10 7:57 PM user-f465
tiL12214_ch03_061-084.indd Page Sec3:61 9/3/10 7:57 PM user-f465 /Users/user-f465/Desktop
3 3 Energy
The wind can be used as a source of energy. All you need is a way to capture
the energy—such as these wind turbines in California—and to live some-
where where the wind blows enough to make it worthwhile.
CORE CONCEPT
Energy is transformed through working or heating,
and the total amount remains constant.
OUTLINE
Work
When work is done on an object, 3.1 Work
it gains energy. Units of Work Motion, Position, and Energy
A Closer Look: Simple Machines Potential energy is the energy
Power an object has due to position.
3.2 Motion, Position, and Energy Kinetic energy is the energy an
Potential Energy
Energy Forms Kinetic Energy object has due to motion.
Energy comes in various forms: 3.3 Energy Flow
mechanical, chemical, radiant, Work and Energy
electrical, and nuclear. Energy Forms
Energy Conversion Energy Conservation
Energy Conservation Energy is transformed from one
Energy Transfer form to another, and the total
Energy Sources Today 3.4 Energy Sources Today amount remains constant.
The main sources of energy Science and Society: Grow Your Own Fuel?
today are petroleum, coal, Petroleum
Coal
nuclear, and moving water.
People Behind the Science: James Joule
Moving Water
Nuclear
Conserving Energy
3.5 Energy Sources Tomorrow Energy Sources Tomorrow
Solar Technologies Alternate sources of energy are
Geothermal Energy solar, geothermal, and hydrogen.
Hydrogen
61
61
