A spherical pressure vessel designed using steel at 97% joint efficiency has inside diameter (ID) of 800 mm and maintains internal pressure of 3N/mm2. The properties of steel are; allowable tensile stress 50 MPa, modulus of elasticity 200GPa and Poisson's ratio 0.25. i) Calculate the shell thickness of the spherical vessel [6 marks] ii) The pressure in the vessel was increased to P, and the vessel new outer diameter (OD) was measured at 830mm. Calculate the value of the pressure P