1 CEGR 212 Mechanics of Materials Final Examination NAME: ______________________________________ The test has 12 questions. You have EXACTLY TWO HOURS. Point value of each problem is as shown. Answer those questions first that you are most comfortable with. Show all work to receive partial credit. Pay close attention to units. Answer the question asked – pay attention to things highlighted in the question. SUBMIT ALL PAGES. Page 4 is a formula sheet. 1. (4 points) Find the reaction at support A for the beam shown below. 2. (4 points) What is the vertical coordinate of the centroid (yc) for the section shown below? All dimensions are in inches. Use the datum (y = 0) as indicated. Do not choose your own datum. 3. (6 points) What is most nearly the centroidal moment of inertia (Ix) of the section shown below? All dimensions are in inches. 4 ft 6 ft 3 ft 20 k 40 k-ft 2 k/ft A B y = 0 1 6 4 8 1.5 1 6 x 1 10 10 x 1 6 x 1
2 4. (6 points) What is the elongation of a rectangular bar (cross section 2 inch x 2 inch, length 4 ft) when it is subjected to an axial load of 80,000 lbs. Assume the material of the bar has the following properties: G = 7,700 ksi, ? = 0.30 5. (10 points) A beam is loaded as shown below. What is the bending moment function in the domain 4