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Equilibrium

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An $\\var{Q}\\,\\text{N}$ load $\\mathbf{Q}$ is applied to the pulley C, which can roll on the cable ACB. The pulley is held in the position shown by a second cable CAD, which passes over the pulley A and supports a load $\\mathbf{P}$. Determine

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Free-Body Diagram

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$\\sum F_x=0$:  $T_{ACB}\\cos 25^\\circ-T_{ACB}\\cos 55^\\circ-P\\cos 55^\\circ=0$

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\\[P=T_{ACB}\\dfrac{\\cos 25^\\circ-\\cos 55^\\circ}{\\cos 55^\\circ}=\\var{kacb}\\,T_{ACB}\\]

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$\\sum F_y=0$:  $T_{ACB}\\sin 25^\\circ+T_{ACB}\\sin 55^\\circ+P\\sin 55^\\circ-Q=0$

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$T_{ACB}=\\dfrac{Q}{\\sin 25^\\circ+\\sin 55^\\circ+\\var{kacb}\\sin 55^\\circ}=\\var{tACB}\\,\\text{N}\\quad\\blacktriangleleft$

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$P=\\var{kacb}\\,T_{ACB}=\\var{P}\\,\\text{N}\\quad\\blacktriangleleft$

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the tension in cable ACB (in N), 

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the magnitude of load $\\mathbf{P}$ (in N).

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