ABSTRACT
Real structures are complicated and have different features in terms of loading application, loading distribution, support restrictions. A free-body diagram is the state of a body without the support restrictions. Free-body diagram is essential to understand and apply the equilibrium condition. Free-body diagram is one of the most important concepts in the subject matter, specifically knowing how to draw and use it in statics, strength of materials, fluid mechanics and other similar subjects. A particle is a body of infinitely small volume and is considered to be concentrated at a point. Every point in a particle can be considered to have the same characteristics. The chapter discusses the equilibrium equation that is applied to idealized particles and the unknown reactions/forces are determined. Although the term ‘particle’ sounds like a tiny object, it more likely means an object dominated by external forces only without deformation.
