$($Show work!$)$

A$)10$pts Draw a free$-$body diagram of the entire truss. Note: Your FBD should look exactly like the one in the figure with the support structures replaced by the appropriate force$($s$).$ The $10$ kip external force should also be resolved properly on the FBD$.$

b$)15$pts For equilibrium of the entire truss, solve for the unknown forces shown in your FBD from $($a$).$

Hint: Do not forget that the external forces create a moment at most points on the lower member $($A$-$F$-$E$-$D$)$

c$)35$ pts Now, use the method of joints to find the force in each member of the truss.

Do this by drawing FBDs at joints A$,$ B$,$ F$,$ E$,$ C$,$ and D$.$ The last point can be used as a check. You can assume all the internal forces to be in tension, i$.$e$.$ force arrow drawn away from the respective point. Then a positive answer shows the force is truly tension and a negative, compression. Be careful with your sequence of points chosen to solve this problem. You want to have a maximum of only two unknowns at each point. This is the basis for the method of joints.

Dr$.$ J$.$ Boffie

d$)5$pts Re$-$draw the FBD of the entire truss as in $($a$)$ above and write on each member, the force computed in part $c$ as its label. Be sure to add a positive $(+)$ or negative$(-)$ sign to indicate if the member is in tension or compression: Don't forget the external forces.

e$)35$pts Use the method of sections to find the forces in members BC$,$ BE$,$ FE of the figure in the problem.

Extra$-$credit towards your homework grade.

$15pt$ Use the other half of the sectioned truss form part e above to solve for the forces in the members $BC,BE$ and FE$.$ i$.$e$.$ If you used the left half after sectioning in part $e,$ use the right half now. Please do not simply repeat answers from part $e$ here. You need to show all working.

$5$ pts For organized and neat work.