Section 3.4 Three-Dimensional Force Systems (page 103) EQUILIBRIUM OF A PARTICLE IN THREE DIMENSIONS (page 1) Z F3 F2 y x F1 1 Figure: 03_009 Copyright @2013 Pearson Education, publishing as Prentice Hall
Section 3.4 Three-Dimensional Force Systems (page 103) EQUILIBRIUM OF A PARTICLE IN THREE DIMENSIONS (page 2) . Newton's Second Law of Motion The motion of a particle of mass m acted upon by a resultant force FR =! F is governed by Newton's Second Law of Motion Fp = mã R where a is the acceleration of the particle. · Equations of Equilibrium A particle is said to be in equilibrium if it remains at rest if originally at rest, or moves with constant velocity if originally in motion. It follows from Newton's Second Law that a particle is in equilibrium when F= EF = 0 That is, when `x !F =0 y !F =0 EF = 0 Z These equations are the Equations of Equilibrium for a particle.
Section 3.4 Three-Dimensional Force Systems (page 103) EQUILIBRIUM OF A PARTICLE IN THREE DIMENSIONS (page 3) · Free-Body Diagram To apply the Equations of Equilibrium for a particle in equilibrium, we imagine the particle to be isolated and free from its surroundings. We take into account all forces acting on the particle. The Free-Body Diagram (FBD) (see, for example, Figure 3-9) shows all forces acting on the particle.