Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Paper format. National Professional Examinations — 07-Str-A1 Elementary Structural Analysis; 3 hours, CLOSED BOOK (an approved Casio or Sharp calculator is permitted). The paper carries eight questions: answer all of Questions 1–5 (6, 24, 16, 16 and 6 + 10 marks) and one only of Questions 6, 7 or 8 (22 marks each), for 100 marks. All three optional questions are worked below, because the complete set is the more useful study resource.
Reference texts. R. C. Hibbeler, Structural Analysis (Ch. 2 determinacy and stability; Ch. 4 shear and moment diagrams; Ch. 6 influence lines; Ch. 8–9 virtual work; Ch. 11 slope deflection); A. Kassimali, Structural Analysis (Ch. 3, 5, 8, 13, 16); K. Leet, C.-M. Uang and A. Gilbert, Fundamentals of Structural Analysis; J. C. McCormac, Structural Analysis: Using Classical and Matrix Methods. For Canadian practice the companion documents are the National Building Code of Canada (Part 4, load combinations) and CSA S16 Design of Steel Structures; this paper is pure analysis, so no design code is invoked in the answers below.
Three figure readings are stated here once and used throughout. (1) In Question 2(b) the two hatched load blocks are drawn from the left end of the beam to the first roller and from the second-last roller to the right end — that is, 0 to 7 m and 13 to 20 m, not merely over the bays named by the dimension string. (2) In Question 2(c) the upper 20 kN acts leftwards at the top of the 1 m riser and the lower 20 kN acts rightwards at its foot, so the applied action is a pure couple and the roller reaction is a hold-down. (3) In Question 6 the 5 kN/m ruling spans the full 16 m width of the sketch, so it is a load on the horizontal projection covering both overhangs and the inclined member. Each reading is the one that makes the arithmetic close on round numbers, which is the usual confirmation on this paper.
