1. The problem statement, all variables and given/known data You are designing the crosspiece for the A-frame structure in the figure below. Beams AB and AC are 3.35 m long and have a mass of 350.0 kg each. How much tension must the crosspiece EF withstand? Assume that the mass of the crosspiece and the friction at points B and C are negligible. http://puu.sh/cnU4U/5763fd520c.png [Broken] 2. Relevant equations torque = (F) (r) (position) F = ma 3. The attempt at a solution i took one section of the ladder thing. i chose the pivot point at force of the pin (Fp) and balance the forces on the free body diagram. the 0.8 is from the horizontal distance between the tension and pivot point http://puu.sh/cnUsg/52dd539959.png [Broken] then i calculated everything and got the answer http://puu.sh/cnUJ3/a9d00e4b98.png [Broken] anyone can explain what i did wrong??