Redundant Members

Problem 438
The center diagonals of the truss in Figure P-438 can support tension only. Compute the force in each center diagonal and the force in BC, DE, and FG.
 

Problem 437
The center panel of the truss in Figure P-437 contains two flexible cables. What load P will cause a compressive force of 20 kN in BD? Then determine which tension diagonal BE or CD is acting and the force in it.
 

In Figure P-420, assume that counter diagonals act from B to E and from E to F in addition to the counter diagonals CD and DG shown in the figure. Assuming that these counter diagonals can support tension only, determine which diagonals are acting and the force in each.