(100,120) em g Bj (50,20) (140,20) a) Evaluate the stiffness matrix for the 2-D element shown in Figure. The coordinates are given in millimeters. Assume plane stress condition. Let E = 210 GPa,v=0.25 and t = 2 mm. b) For the element, the nodal displacements are given as u, = 2.0 mm, v, = 1.0 mm, u = 0.5 mm,v = 0.0 mm,u, = 3.0 mm,v, = 1.0 mm Determine the element stresses,, and T.,. (35 P)