1. The problem statement, all variables and given/known data The right-angle bar with equal legs weighs 6.0 lb and is freely hinged to the vertical plate at C. The bar is prevented from rotating by the two pegs A and B fixed to the plate. Determine the acceleration a of the plate for which no force is exerted on the bar by A either B peg or . I have attached an image of the question 2. Relevant equations 3. The attempt at a solution I'm pretty sure this is a striaghtforward question but I think I'm missing something. First I summed the forces in the x and y direction. ƩFy = may = Cy - mg Cy = mg ƩFx = max = Cx Then I took the moment about the origin. I assigned the origin as being inbetween A and B. And I found the center to be (2,6) ƩM = -1/6*mg -8/12*Cx + 8/12*Cy Cx = 3/4*mg ax = a = Cx/m = [(3/4)mg]/m = (3/4)g But the answer should be 3g. Where am I making my mistake? Any help would be appreciated.