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Homework Statement
The beam ABC is1000LBs and its center of mass is given as 6.5ft to right of B. B is a pin joint. A & D are frictionless rollers. Find tension in cable.
Homework Equations
Call the tension in the cable T.
Trig shows us that the lefthand triangle is 45 degrees at ABD and the righthand triangle is 15.5 degrees at BCD.
Torque due to wt of load and mass of beam are clockwise and negative; torques due to T are ccw and positive.
The Attempt at a Solution
So the torque at B should be: (6.5ft)(1000Lb) + (12ft)(3000LB) + (18ft)(sin15.5)T + (5ft)(sin45)T=0
This yields a T of 5114; the book shows the answer as 6770.
What am I missing?
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