ME 121 FALL 2004 HOMEWORK ASSIGNMENT 9 - Nov 12, 2004

Problems and Reading Assignments are from DYNAMICS (3rd ED.), Bedford & Fowler (Prentice Hall, 2002)

GOALS

• Provide working knowledge of rigid body (RB) planar dynamics, in terms of translation of CM and rotation about CM.
• Relation of linear/angular accelerations and forces/torques in rigid body motion.
• Free Body Diagrams are DIFFERENT from Acceleration Diagrams. We equally need both.
• Motion of a RB about a fixed axis vs. general planar motion.

• Special attention to SI units in dynamics (kg, m, s, N).
• Use of Newton's 2nd law for linear and rotational components of motion of rigid bodies.
• Use of linear and angular momentum in planar dynamics.
• Use FBD's in simple components and systems.
• Use of acceleration diagrams in simple components and systems.
• Working knowledge of mass moment of inertia for simple engineering components (rods, spheres, cylinders, hoops, combinations.)

Reading assignment

Chapter 17( Planar kinematics of rigid bodies): all; Chapter18(Planar dynamics of rigid bodies): Sections 18.1 to 18.4. Notice the Appendix on Moments of Inertia.
Make sure you study especially carefully ALL the solved examples.
If you want additional practice, note that even-numbered problems have answers in back of book.

Problems

1.   Problem 17.121

2.   Problem 17.130

3.   Problem 17.132

4.   Problem 17.147

5.   Problem 18.3

6.   Problem 18.20

7.   Problem 18.26

8.    Problem 18.40