Statics — Forces & Equilibrium
Resolve forces, balance moments, read a free-body diagram, solve a truss joint, and decide whether the crate slides — every number live and unit-checked.
Statics is the engineering of things that do not move: a bridge, a bracket, a bookshelf. The whole subject rests on one sentence — the forces and moments on a stationary body must sum to zero — and the engine's unit tracking turns that sentence into arithmetic you can trust. This is the foundation every later engineering course builds on.
- 01 Forces have direction — resolve them into components ELI5: a force pulling at an angle does some of its work sideways and some upward. Split it into a horizontal part F·cos θ and a vertical part F·sin θ, handle…
- 02 Equilibrium — the sums that must be zero ELI5: if a body sits still, every push is cancelled by an equal pull. Add up the horizontal forces — they must be zero. Same for vertical. Those two equations…
- 03 Moments — the turning effect of a force ELI5: push a door near the hinge and nothing happens; push at the handle and it swings. The turning effect is the moment = force × distance from the pivot. A…
- 04 Distributed loads — spread weight to a single point ELI5: a beam doesn't carry its load at one spot — snow, water, or its own weight presses along its whole length. A uniform load of w (force per metre) over…
- 05 A truss joint — method of joints ELI5: a truss is a triangle of straight members, each only ever pulled or pushed along its length. At any joint the forces must balance — so a single pin…
- 06 Friction — will it slide? ELI5: friction resists sliding up to a limit, f_max = μ·N, where N is how hard the surfaces press together. Push below that limit and nothing budges; exceed it…
next course: Mechanics of Materials — Stress & Strain →