Mechanics
- Equilibrium: ΣFx = 0, ΣFy = 0, ΣM = 0
- Bending stress σ = Mc/I; axial stress σ = P/A
- Simply supported beam, uniform load: Mmax = wL²/8
Fluids and water
- Continuity: Q = A₁V₁ = A₂V₂
- Rational method: Q = CiA
- Manning: V = (1.49/n) R^(2/3) S^(1/2) in US units
Geotechnical
- Effective stress: σ′ = σ − u
- Void ratio e = Vv/Vs; porosity n = e/(1 + e)
- Rankine active coefficient Ka = tan²(45° − φ/2)
Transportation and economics
- Stopping sight distance = 1.47Vt + V²/(30(f ± G))
- Traffic flow q = k·v
- Present worth P = F/(1 + i)ⁿ
Test yourself on FE
Reading a summary is the easy part. Take the free 10-question diagnostic to see which of these domains you actually have, then drill the rest.