The figure shown illustrates the connection of a steel cylinder head to steel pressure vessel using 12 bolts. The cylinder stores gas at a maximum gas pressure pg = 3.0 N/mm². In order to settle the gasket for leak proof, initial tightening force of P = 30 kN is applied to each Metric Grade 9.8 bolt before the pressure is applied in the cylinder. The pressure cylinder diameter D = 120mm. Assume that the load is distributed equally on bolts and that at each bolt location, the stiffness of the clamped members ke is 3 times the stiffness of the bolt. (a) Using the design factor of 3 on proof strength, determine the tensile stress area A, needed for the bolt D) Suggest the size of the bolt to be used. i.If the lower quality bolts of Metric grade 4.6 were to be used, what would be the size of the bolt? ii.Is the size of the bolt you get reasonable for the intended application? Give reasons.