. Consider the disk with a centerline hole of radius 20 shown spinning at a rotational velocity of w radians/second. 3.0 20 x, u 60 80 E-Young's modulus p = mass density v = Poisson's ratio 1.0 Idealize the structure as an assemblage of 2 two-node elements and calculate the steady-state (pseudostatic) equilibrium equations. (Note that the strains are now du/ax and u/x, where u/x is the hoop strain.)