1. The problem statement, all variables and given/known data The 1.1m bar is supported by a ball and socket support at A and 2 smooth walls. The tension in the vertical cable CD is 1kN. Draw the Free Body Diagram of the Bar. Determine the Reactions at A and B. 2. Relevant equations Equillibrium equations. Perhaps the vector projections...?? 3. The attempt at a solution I drew the FBD: and you can see the beginnings of my equillibrium equations. I am fairly sure these are all correct except for the fact By should not be there. The tension CD can only pull normal to the location its given - ie, along the y axis if its directly under the object. The smooth surface gives a normal force to the object, I experimented by resting pencils together that this would exert an x, z force so i broke them into components. The ball and socket is basically a hinge, so it exerts axial forces in the x, y, z. My confusion is this: The tension will obviously produce a moment about A pulling the rod downward along the y axis. The only thing preventing this descent is the combined reactions of the wall's x and y forces. Together they must produce a positive force along the y direction. This force must be equal to the relationship: 0.4mTCD = 1.1mBy 0.4kN-m= 1.1mBy By = 0.4/1.1 kN-m Now, By does not exist because the smooth surfaces can only exert forces normal to their plane. However, could it be the cross product of the two forces...? If so, then how do we find it? By projecting By along the two surfaces?