SECTION B-Answer any THREE of these four questions [203=60 marks] QUESTION #3 3D Rigid Body Equilibrium 2 m x 6 m 3 m 3 m D 4 m F2 (350j) N B [20 marks] F = (-800k) N Figure 2 (Courtesy of Prentice Hall) As shown in Figure 2, a bent rod AB is supported from the ceiling by two cords BC and BD at B, and from the floor by a smooth journal bearing at A. The rod is subjected to an 800-N downward force F and a 350-N horizontal force F2. (a) Express the direction in the cords as unit vectors pointing away from B. (b) State the unknowns for this system. [3 marks] [3 marks] (c) Write of the set of equilibrium equations that will be used to solve this system. Do not solve the system as yet. For your equations, include the values of quantities that are known while leaving unknown quantities their symbolic form. (d) Compute the x, y, z components of force reactions at the bearings. [6 marks] [8 marks]