Knowledge area 4 of the FE Civil exam: 8–12 of the 110 questions. The subtopics NCEES lists, how they are tested and worked practice problems with solutions.
110 questions on the real 5 hours 20 minutes clock, weighted to the NCEES specifications, with a score by knowledge area and a worked solution for every answer.
Or start the free Statics drillFrom the NCEES FE Civil CBT exam specifications, knowledge area 4.
Statics questions ask for support reactions, truss member forces, centroids, moments of inertia and friction limits. Draw the free-body diagram first, take moments about the point that removes the most unknowns, and check units. The Reference Handbook section on statics lists centroids and moments of inertia of common shapes.
On exam day the relationships you need are in the Reference Handbook section on Statics. The handbook is the only reference allowed, so practice finding each formula in it rather than memorizing a separate sheet.
Work each problem with your calculator and the handbook, then open the solution.
Problem 1 · Area properties
A solid circular shaft has a diameter of 80 mm. The radius of gyration of its cross-sectional area about a diameter is most nearly:
Answer: A: 20.0 mm
For a circle, I = πd⁴/64 and A = πd²/4, so k = √(I/A) = √(d²/16) = d/4 = 80/4 = 20.0 mm.
Area properties · Reference Handbook: Statics
Problem 2 · Centroid of area
A T-section has a horizontal flange 200 mm wide and 20 mm thick sitting on top of a vertical web 20 mm thick and 180 mm tall, so the total depth is 200 mm. The distance from the bottom of the web to the centroid of the section is most nearly:
Answer: C: 142.6 mm
Web: A = 20(180) = 3,600 mm², ȳ = 90 mm. Flange: A = 200(20) = 4,000 mm², ȳ = 180 + 10 = 190 mm. ȳ = (3,600·90 + 4,000·190)/7,600 = 142.6 mm from the bottom.
Centroid of area · Reference Handbook: Statics
Problem 3 · Frames and trusses
A hand-operated crimping tool consists of two handles pinned together. A hand force of 120 N is applied perpendicular to each handle at 150 mm from the pin, and the jaws contact the workpiece 25 mm from the pin on the other side. The force each jaw applies to the workpiece is most nearly:
Answer: C: 720 N
Treat one handle as a free body and take moments about the pin: F_jaw(25) = 120(150), so F_jaw = 720 N. The pin then carries 720 + 120 = 840 N, which is a common answer when the wrong force is reported.
Frames and trusses · Reference Handbook: Statics
Problem 4 · Static friction
Select all that apply.
Which statements about dry (Coulomb) friction are true? Select all that apply.
Answer: A: The static friction force can take any value from zero up to μ_s N; B: The maximum static friction force is proportional to the normal force; D: The coefficient of kinetic friction is usually smaller than the coefficient of static friction
Static friction adjusts to whatever is needed for equilibrium, up to the limit μ_s N, which is proportional to the normal force. Once sliding begins, the friction force is μ_k N, and μ_k is usually less than μ_s.
Static friction · Reference Handbook: Statics
More FE Civil practice problems from every knowledge area
Sit the full exam under the real clock
110 questions on the real 5 hours 20 minutes clock, weighted to the NCEES specifications, with a score by knowledge area and a worked solution for every answer.
Or start the free Statics drillThe NCEES FE Civil specification lists 8–12 questions on Statics, out of 110. Every examinee gets the same number per knowledge area.
Resultants of force systems; Equivalent force systems; Equilibrium of rigid bodies; Frames and trusses; Centroid of area; Area moments of inertia; Static friction.
In the NCEES FE Reference Handbook, which appears on screen during the exam: the Statics section. Practice with your free copy from MyNCEES so you know where each relationship sits.
Original independent practice questions written to the published NCEES exam specifications. Not affiliated with or endorsed by NCEES (National Council of Examiners for Engineering and Surveying).