A thick-walled cylinder with 0.3 m and 0.4 m internal and external diameters, respectively, is fabricated of a material whose ultimate strength is 250 MPa. If v = 0.3, find: (a) For Po= 0, the maximum internal pressure to which the cylinder may be subjected without exceeding the ultimate strength. (b) For P = 0, the maximum external pressure to which the cylinder can be subjected without exceeding the ultimate strength. (c) The radial displacement of a point on the inner surface for case (a).