By using the finite element method, solve the given 2-dimensional truss system (Figure 2). Nodes 1 and 3 are pinned support while node 2 is free to move in both X, Y directions. E is the elasticity modulus and A is the cross-sectional area of the truss elements. The units are kN and m. a. [8 Points] Determine Element stiffness matrix in global coordinates b. [7 Points] Determine the horizontal displacement of node 2, c. [5 Points] Determine the nodal forces of the truss elements. E=120000 kN/m 10KN A=0.10m 2 2m 3m Figure 2. Truss system A=0.20m 4m 4 Y X