$2$ Method of Sections

$3.$ The given truss members have equal lengths. Assume that the force at $B,E,$ and $D$ has the magnitude of $F_B=40kN,F_E=10kN,$ and $F_D=30kN,$ respectively.

$($a$)$ Draw a free$-$body diagram for the truss.

$($b$)$ Use the diagram to calculate the reaction forces at A and C $.$

$($c$)$ Use the method of sections to compute the forces in the members of the truss $AB,BE,$ and ED$.$

$($d$)$ Identify which force in the members of the truss is a compression or a tension.