1. King Fahd University of Petroleum & Minerals Mechanical Engineering Dynamics ME 201 BY Dr. Meyassar N. Al-Haddad Lecture # 38

2. Chapter 18 Kinetics of a Particle ; Work & Energy Objectives –To develop the principle of work and energy and apply it solve problems that involve force, velocity, and displacement. –To apply the theorem of conservation of energy to solve kinetic problems

3. TranslationRotation General

4. Principle of Work and Energy Translation Rotation

5. 14.5 Conservative Forces and Potential Energy Conservative Force: independent of the path –Example weight & spring force –The work done by the frictional force -> depends on the path -> non-conservative-> the work is dissipated (heat) Potential Energy: “capacity for doing work” –Energy comes from the motion -> Kinetic energy –Energy comes from the position-> Potential energy

6. Gravitational potential Energy :

7. Elastic potential energy :

8. Conservation of Mechanical Energy Special case for 0, 45, and 90 o

9. m =10-kg, k = 800 N/m  = ? Example 18-7

10. Example 18-8

11. m D =10-kg m R =5-kg rod AB.  = ? rolls without slipping Neglect friction Example 18-9