[5]\ 7. A cylindrical shell made of mild steel plate and

1.2m

in diameter is to be subjected to an internal pressure of

1.5M(N)/(m)

. If the material yields at

200M(N)/(m^(2))

, calculate the thickness of the plate on the basis of the following three theories, assuming a factor of safety 3 in each case:\ i) maximum principal stress theory\ ii) maximum shear stress theory\ iii) maximum shear strain energy theory

7. A cylindrical shell made of mild steel plate and 1.2m in diameter is to be subjected to an internal pressure of 1.5MN/m. If the material yields at 200MN/m2, calculate the thickness of the plate on the basis of the following three theories, assuming a factor of safety 3 in each case: i) maximum principal stress theory ii) maximum shear stress theory iii) maximum shear strain energy theory