1. Chapter 11Energy Energy LecturePLUS Timberlake

2. Energy • Makes objects move • Makes things stop • Energy from sun plants foods we eat energy to live • We need energy to “do work” LecturePLUS Timberlake

3. Work is done when • Go up stairs • Play soccer • Lift a bag of groceries • Ride a bicycle • Breathe • Heart pumps blood • Water goes over a dam LecturePLUS Timberlake

4. Potential Energy Is stored energy Examples • Water behind a dam • Compressed spring • Chemical bonds in gasoline or coal • Food LecturePLUS Timberlake

5. Kinetic Energy Is energy of motion Examples • Hammering a nail • Water flowing over a dam • Working out • Boxing • Burning gasoline LecturePLUS Timberlake

6. Some Forms of Energy • Mechanical • Electrical • Thermal (heat) • Chemical • Radiant (light) LecturePLUS Timberlake

7. Learning Check E1 A. A car uses more fuel when the air conditioner is on. True (1) or False (2) B. An apple hanging on a tree has potential energy that can turn into both mechanical or chemical energy. True (1) or False (2) LecturePLUS Timberlake

8. Solution E1 A. A car uses more fuel when the air conditioner is on. True (1) B. An apple hanging on a tree has potential energy that can turn into both mechanical or chemical energy. True(1) LecturePLUS Timberlake

9. Learning Check E2 Suppose you place water in a freezer. A. The water particles move 1) faster 2) slower 3) the same B. The water will get 1) hotter 2) colder 3) stay the same C. The temperature of the water will be 1) higher 2) lower 3) the same LecturePLUS Timberlake

10. Solution E2 Suppose you place water in a freezer. A. The water particles move 2) slower B. The water will get 2) colder C. The temperature of the water will be 2) lower LecturePLUS Timberlake