MEEG 2003

Teaching Assistant, University of Arkansas, Mechanical Engineering, 2017

Class Overview

Summary: Equilibrium and resultants of force systems in a plane and in space; analysis of structures, friction, centroids, moments of inertia, and virtual work method. Methods of analysis are emphasized.
Corequisite: MATH 2574 or MATH 2574C.
Prerequisite: PHYS 2054. (Typically offered: Fall, Spring and Summer)



Ing-Chang Jong


Kashu Yamazaki

Lecture Information

Text Book: Jong, I. C., Engineering Mechanics: Statics, Second Edition, 2013, Great River Learning, Debuque, IA.


9 collections of homework (each worth 5 points), 6 quizzes (each worth 10 points), 3 tests (each worth 100 points), n pop quizzes (each worth 5 pts), and a final exam (worth 100points). The total score you can possibly earn in this course may, therefore, be 505 + 5n points.

Drill Sessions

Time: 6:30-8:30, Tuesdays
Location: BELL 2267

Lecture Topics

  • Test1 - 9/20 (Ch.1 ~ Ch.3)

Summary: Fundamental concepts/laws, addition and resolution of forces, equilibrium of particles, action to rotate a body, and moments with vector algebra

  • Test2 - 10/30 (Ch.4 ~ Ch.6)

Summary: Equivalent and equipollent system, rigid-body equilibrium in a plane/space, POM, centroids and centers of gravity, areas/volumes, distributed loads, area moments of inertia, PAT, and trusses

  • Test3 - 12/4 (Ch.6 ~ Ch.8)

Summary: Frames and machines, friction between rigid bodies, belt friction, work, displacement center, and virtual work

  • Final Exam - 12/11 (Ch.1 ~ Ch.8)

Important Topics

Principle of Moments (POM)

  1. Resultant = sum of components
  2. Moment of resultant = sum of moments of components

Parallel-Axis Theorem (PAT)

The moment of inertia of a body about a given axis is related to the moment of inertia about a centroidal axis parallel to the given axis as follows:


Work is energy in transition to a system due to force or moment acting on the system through a displacement. Note that Heat is energy in transition to a system due to temperature difference between the system and its surroundings. Work differs from energy in that workis nota property possessed by a system, while energy (e.g., kinetic energy or potential energy) is. Work is a boundary phenomenon.

Virtual Work Method

Three major steps for virtual work method:

  1. Draw the free-body (FBD) diagram.
  2. Draw the virtual-displacement diagram (VDD) with a strategy, which gives the free body a compatible virtual displacement in such a way that the one specified unknown, but no other unknowns, will be involved in the virtual work done.
  3. Set the total virtual work done to zero in order to solve for the unknown.


  • Jong, I. C., “Kindling Students’ Interest in Virtual Work Method: Advantages and Challenges,” Proceedings of the 2004 ASEE Midwest Section Conference, Pittsburg, Kansas, September 29 - October 1, 2004.
  • Jong, I. C., “Teaching Students Work and Virtual Work Method in Statics: A Guiding Strategy with Illustrative Examples,” Proceedings of the 2005 ASEE Annual Conference & Exposition, Portland, Oregan, June 12-15, 2005.
  • Jong, I. C., “From Conventional Method to Virtual Work Method in Statics: Three Major Steps and One Guiding Strategy,” Proceedings of the 2005 ASEE/AaeE 4th Global Colloquium, Star City, Sydney, Australia, September 26-29, 2005.
  • Jong, I. C., “Learning the Virtual Work Method in Statics: What Is a Compatible Virtual Displacement?,” Proceedings of the 2006 ASEE Annual Conference & Exposition, Chicago, Illinois, June 18-21, 2006. (Also presented at the 5th ASEE Global Colloquium on Engineering Education, Rio de Janeiro, Brazil, October 8-12, 2006.)