A cylindrical shell 2 m long has a wall thickness of 15 mm. Initially, the cylinder contains fluid at atmospheric pressure then the ends of the cylinder are closed and additional fluid 340 cm3 is pumped into the shell. It was observed that internal fluid pressure becomes 25 N/mm2. Assuming fluid to be incompressible, determine the initial diameter of shell in mm. Take μ = 0.3 and E = 2 × 105 N/mm2 [up to 2 decimals]