a) A steel disc of uniform thickness has a diameter of 1.6 m and rotates at 2400 rpm. Determine the radial and circumferential stresses at the center and the outer radius of the disc. b) A central hole of 0.32 m diameter is then drilled on the disc. Determine the circumferential stresses on the inner and outer radius. Assume Poisson's ratio u = 0.33 and density of steel p = 7800 kg/m. Note that except for the characteristic equations given below, all other equations used must be derived. The characteristic equations for stresses B on the walls of a thin rotating disc are; (1+3v) B (3 + v) 8 por ando, = A +2 por. 7. 8 0 = A --