Statics
Statics is the study of bodies in equilibrium, where all forces and moments balance. The exam tests your ability to draw free-body diagrams and apply the equilibrium equations to trusses, frames, and simple machines.
Equilibrium and Free-Body Diagrams
A body in equilibrium satisfies sum of forces = 0 in each direction and sum of moments = 0 about any point. The free-body diagram, showing every external force and reaction, is the essential first step. In two dimensions this yields three independent equations.
Resultants and Moments
Concurrent forces combine by vector addition; two perpendicular forces of magnitude a and b give a resultant of sqrt(a^2 + b^2). A moment equals force times perpendicular distance (M = F·d) and measures the tendency to rotate a body about a point.
Friction and Area Properties
Maximum static friction is F = mu·N, proportional to the normal force and independent of contact area. Centroids and moments of inertia of areas (with the parallel-axis theorem) feed directly into strength-of-materials calculations for bending and buckling.