고체역학 (Gere) — Tension, Compression, and Shear: Problem 1.3-6

1.3-6 Consider the plane truss with a pin support at joint 3 and a vertical roller support at joint 5 (see figure). (a) Find reactions at support joints 3 and 5. (b) Find axial forces in truss members 11 and 13. Given values from the figure: - Horizontal external force at joint 1: \(60\text{ N}\) (to the right). - Vertical external force at joint 6: \(20\text{ N}\) (downward). - Vertical external force at joint 7: \(45\text{ N}\) (downward). - Dimensions: Distance 1-2 = \(2.5\text{ m}\), 2-3 = \(2\text{ m}\), 3-4 = \(1\text{ m}\). Height = \(2\text{ m}\). - Joint coordinates (assuming origin at 1): \(1(0,0)\), \(2(2.5,0)\), \(3(4.5,0)\), \(4(5.5,0)\), \(5(0,2)\), \(6(2.5,2)\), \(7(4.5,2)\), \(8(5.5,2)\). - Support at joint 3: Pin (horizontal and vertical reactions). - Support at joint 5: Vertical roller (horizontal reaction against the vertical wall).