Calculate [k] for active degrees of freedom for square element below with side length and thickness 1M. What is det [k]=? Calculate force vector due to gravitational load (g) and concentrated load F applied 0.75M from node 1. Neglect nonmechanical strain. X 4 1 3 E=1 N/mm p=1 g/cm gravity g~9.81M/sec 2 F(N) Nodes 1,2,3 and 4 are fixed in x direction Poisson ratio v=0.3