Practice Question: Internal Force in a Truss Member

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Solution

Answer: A) 106 kip

 Vertical Summation of forces at Point 3 = 0:

\[F_{b}\ sin \phi\ - 75\ kip = 0\]

\[F_{b}\ sin \phi\ = 75\ kip\]

 where:

\(\phi =45\ degree\\\)

Solve for \(F_{b}\):

\[F_{b} = \frac{75\ kip}{ sin\ 45} = 106\ kip\\\]

 

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