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.
Call the tension in the cable T.
Trig shows us that the left-hand triangle is 45 degrees at ABD and the right-hand 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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