The two rods (A-B and B-C) shown in the left panel of Figure 4.1 are connected by pins at A, B,and C. The cross sections of A-B and B-C are

12mmx14mm and 8mmx8mm, respectively. The stress-strain relation shown in the right panel is for the material used to make the two rods, where Ei is the slope of the stress-strain curve for stresses between 0 and 80 MPa and E2 is the slope for stresses larger than 80 MPa. The lengths of the two rods can be determined using the angle between rod AB and BC (see the figure) and the vertical distance (2.5m) between points C and B. Note that the vertical distance between points A and B is also 2.5 m. a) Given the conditions above, find the axial elongation for each rod when subjected toP=10KN. b) Find the final lengths of rods AB and BC after removal of the load P. c) Reconsider the structure in the figure. In order to make sure that neither rod experiences permanent deformation, what is the maximum load P that can be applied at point B?