Design a cylindrical pressure vessel to carry com- pressed air for a self-contained breathing apparatus for use by firefighters when operating in smoke- filled buildings. The minimum inside diameter is to be 6.00 in and the length of the cylindrical portion of the tank is to be 15.0 in It must withstand a ser- vice pressure of 450 psi. Use a design stress of s./8 to account for a large number of pressurization cycles. Also, check the final design for its ability to withstand a maximum pressure of 900 psi by com- puting the design factor based on yield strength. The tank is to be made from aluminum alloy 6061- T6. Compute the weight of just the cylindrical portion.