1. Conservation of Energy and Power
Sections 5.3 and 5.4

2. Objectives
Conservation of Mechanical Energy
Identify situations in which conservation of mechanical energy is valid.
Recognize the forms that conservation of energy can take.
Solve problems using conservation of energy.

3. Mechanical energy is the sum of kinetic energy and all forms of potential energy.

4. Mechanical energy is often conserved
Mechanical energy is often conserved. In the absence of friction, the total mechanical energy remains the same. This is called conservation of mechanical energy.

5. Mechanical energy can change form from potential energy to kinetic energy, or from potential energy to kinetic energy.

13. Objectives
Power
Relate the concepts of energy, time, and power.
Calculate power in two different ways.
Explain the effect of machines on work and power.

14. The rate at which work is done is called power.

16. Many mountain roads are built so that they zigzag up the mountain rather than go straight up toward the peak. Discuss the advantages of such a design from the viewpoint of energy conservation and power.