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Statics  Coplanar Force Systems 
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#1
Sep1709, 08:20 PM

P: 41

The problem statement:
My relevant equation: [itex]\phi[/itex] will be the angle between the X axis and [itex]F_{CO}[/itex] [tex]\theta = \phi + \arcsin\left(\frac{3}{5}\right)[/tex] My attempt at a solution: [tex]\Sigma F_{x} = 0:[/tex] [tex]F_{CO}\cos\phi  F_{BO}\frac{4}{5} = 0[/tex] [tex]F_{CO} = \frac{F_{BO}\frac{4}{5}}{\cos\phi}[/tex] [tex]\Sigma F_{y} = 0:[/tex] [tex]F_{AO}  F_{BO}\frac{3}{5}  F_{CO}\sin\phi = 0[/tex] Combining terms and substituting the equation found for [itex]\Sigma F_{x} = 0[/itex] into [itex]\Sigma F_{x} = 0:[/itex] [tex]F_{AO}  \frac{3}{5}F_{BO}  \frac{4}{5}F_{BO}\tan\phi = 0[/tex] [tex]9kN  \frac{3}{5}8kN  \frac{4}{5}8kN\tan\phi = 0[/tex] [tex]\phi = \arctan\left(\left(9+\frac{24}{5}\right)*\frac{5}{32}\right)[/tex] [tex]\phi = 65.12^{\circ}[/tex] [tex]\theta = 102^{\circ}[/tex] The published value of [itex]\theta[/itex]: [tex]\theta = 70.1^{\circ}[/tex] I don't know what I did wrong. TIA for any response. 


#2
Sep1709, 09:25 PM

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#3
Sep1709, 09:54 PM

P: 41

Jay, thank you sir!



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