a plane truss is subjected to a loads 2P and P at joints B and C, respectively, as shown in figure part a.The truss bars are made of two L102 x 76 x 6.4 stell angles having an ultimate stress tension equal to 390 MPa (cross-sectional are of the two angles, A = 2180 mm^2). The angles are connected to a 12 mm-thick gusset plate at C with 16-mm diameter rivets; assume each rivet tranfers an equal share of the member force to the gusset plate. The ultimate stresses in shear and bearing for the rivet steel are 190 MPa and 550 MPa, respectively. Determine the allowable load P if the safety factor of 2.5 is desired with resect to the ultimate load that can be carried. (Consider tension in the bars, shear in the rivets, bearing between the rivets and the bars, and also bearing between the rivets and the gusset plate. Disregard friction between the plates and the weight of the truss itself.)