FreeBody Diagram

In practical engineering problems, many actual physical situations and structures can be reduced to particle equilibrium problems and represented by a sketch. A freebody diagram can be obtained by identifying a significant position of an isolated object with all forces acting on it. For example, the structure of two hanging blocks connecting to the ceiling can be represented by two freebody diagrams as two individual equailibrium situations.

The two important concerns in constructing the freebody diagram are the boundary of interest and the choice of coordinate. The selected physical situations and structures can then be transformed into freebody diagram through the techniques of idealization by applying the Newton's third law.