Engineering Mechanics
Forces Systems and Resultants
Chapter 2
Lecturer: Nuha H. Aljubory
Civil Engineering Department,
College of Engineering,
University of Mosul.
References:
1-Vector mechanics for engineers : Statics by Ferdinand P.Beer.
2- Engineering Mechanics : Statics by R.C. Hibbeler.
3- ‫ نزار جبريل الياس‬.‫د‬/‫الجزء األول‬-‫علم السكون‬-‫الميكانيك الهندسي‬
4- Engineering Mechanics : Statics by J.L. Meriam
1
Contents
• Introduction
• Force on a Particle: Resultant
of Two Forces
• Sample problem
• Rectangular Components
• Resultant of Several
Concurrent Forces
• Sample problem
• Sample problem
• Sample problem
• Moments
• Moments about a Point
• Resultant of Moment
• Sample problem
• Sample problem
• Couples
• Equivalent Couples
• Sample problem
• Force-Couple Systems
• Sample problem
Introduction
Force on a Particle:
Resultant of Two Forces
Rectangular Components
In many problems, it is useful to resolve a force into
two components that are perpendicular to each
other. Figure 2.14 shows a force F resolved into a
component Fx along the x axis and a component Fy
along the y axis. The parallelogram drawn to obtain
the two components is a rectangle, and Fx and Fy
are called rectangular components.
The x and y axes are usually chosen to be
horizontal and vertical, respectively, as in Fig.
2.14; they may, however, be chosen in any two
perpendicular directions, as shown in Fig. 2.15
Resultant of Several Concurrent Forces
Moment
Couple