Spherical shell is homogeneous isotropic material. If spherical shell is bounded(fixed) to the surrounding medium, and contains a gas under pressure of magnitude Po as following figure. Assume there is no bod force. spherical shell gas solid (1) Determined boundary conditions for this spherical shell. (2) Express the equilibrium equation in terms of displacement for this problem. (3) Determined the displacement field of the shell (4) Determined the strain field of the shell Po (5) Find the normal stress on the interface between spherical shell and surrounding medium. (6) Consider a spherical hole in infinite body subject to internal pressure Po as shown in the following figure, please find the displacement field of the solid according to the result of problem (3) gas fixed Po