Topic 5 – Energy

Goal: For this Topic, students will investigate how the concepts of work and mechanical energy provide an alternative description for the motion of objects. Students will also study power, the quantity that describes the rate of energy transfer.

Objectives:

•       Explain the concept of work. Identify when work is either positive or negative, and be able to calculate the work done on a mechanical system.

•       Define kinetic energy and states its relationship to the work done on an object. Give examples of conservative and nonconservative forces.

•       Define gravitational potential energy. Potential energy is a property of a system.

  •        Describe the concept of conservation of mechanical energy.

•       When nonconservative forces act the extended work-energy theorem, see equation 5.13, must be used.

•       State Hooke’s law. Calculate elastic potential energy and apply it to the work-energy theorem

•       Describe, with examples, different forms of energy and their transfer between forms.  Apply the law of conservation of mechanical energy to solve problems where work is done by nonconservative forces.

•       Mathematically define power, and solve problems involving power.  Define, in general, the center of mass of an object.

•       Use graphical relationships to analyze the work done by a varying force.

Assignments:

1. Read and Take Notes Chap 5.1 – 5.2

2. Read & take notes Chap 5.3; Problems 1, 4, 7, 13

3. Read & take notes Chap 5.4; Problems 18, 19, 23

4. Read & take notes Chap 5.5 – 5.6; Problems 20, 25, 31

5. Read & take notes Chap 5.7; Problems 32, 36, 47

6. Problems 59, 61

7. Review for Test

8. Chapter 5 test