Statics

Equilibrium

The state in which all forces and all moments acting on a body sum to zero.

A body is in static equilibrium when it has no linear or angular acceleration. In two dimensions this gives three independent equations: forces in x sum to zero, forces in y sum to zero, and moments about any point sum to zero.

Because the moment equation holds about any point, choosing that point well is a free simplification. Taking moments about a location where an unknown force acts eliminates that unknown from the equation entirely.

How much of the FE Civil exam is Statics?