Due to settlement of soil, a recently planted tree has started to lean. To straighten it, the cable system shown is used, where a turnbuckle on cable AB is periodically tightened to keep the cable taut as the tree gradually straightens. If the force in cable AB is 395 N, determine the force in cable CBD.
(see attached diagram)
The Attempt at a Solution
*hint* A FBD of the pulley at B is recommended to begin this problem. Isolating pulley B from its surrounding requires a closed surface passing through cables AB and BCD (along both segments BC and BD). The problem has a symmetry that becomes apparent with an orthogonal coordinate system having one axis aligned with AB.
What does the hint mean by "closed surface passing through cables AB and BCD"?
I don't know what the question means by the force in cable CBD. Is it referring to total tension or something?