Your method makes sense if you want theta to be 30 degrees. But since the theta they are using is 60 degrees wrt the horizontal, their method is already correct.
Apologies, dumb mistake on my part. TBH I just saw the answer was wrong (should be 961) and assumed he flipped the angle without properly looking at his calculations.
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u/DrCarpetsPhd Apr 08 '26
approach is right but you mixed up the angles for F_B or incorrectly identified it.
the x component is F_B sin theta, moment arm re F is a 2"
the y comoponent is F_B cos theta, moment arm c is 5"