Coplanar concurrent force system – a system of forces whose lines of action lie in one plane and intersect at a single point.
In such a system, moment equilibrium is always satisfied. A coplanar concurrent force system can be reduced to a resultant force.
A typical example is a truss joint, where equilibrium can be solved using only force balance in two perpendicular directions.
Learn more about the concurrent coplanar force system in the article: Calculating normal forces in trusses – method of joints, which is part of a series on internal forces analysis.
