$12-1.$ Determine $($approximately$)$ the force in each member of the truss Assume the diagonals can support either a tensile or a compressive force.

Ans

$F_{BF}=2\mathrm{.}08k(T),F_{AE}=2\mathrm{.}08k(C)$

$F_{EF}=1\mathrm{.}67k(C)$

$F_{AB}=1\mathrm{.}67k(T)$

$F_{BD}=2\mathrm{.}08k(T),F_{CE}=2\mathrm{.}08k(C)$

$F_{DE}=1\mathrm{.}67k(C)$

$F_{BC}=1\mathrm{.}67k(T)$

$F_{AF}=4\mathrm{.}25k(C)$

$F_{BE}=2\mathrm{.}50k(C)$

$F_{CD}=5\mathrm{.}25k(C)$

$12-2.$ Solve Prob. $12-1$ assuming that the diagonals cannot support a compressive force.

Ans.

$F_{AE}=F_{CE}=0$

$F_{BF}=4\mathrm{.}17k(T)$

$F_{EF}=3\mathrm{.}33k(C)$

$F_{AB}=0$

$F_{BD}=4\mathrm{.}17k(T)$

$F_{DE}=3\mathrm{.}33k(C)$

$F_{BC}=0$

$F_{AF}=5\mathrm{.}50k(C)$

$F_{BE}=5\mathrm{.}00k(C)$

$F_{CD}=6\mathrm{.}50k(C)$