A gas cylinder (closed thin-walled cylindrical pressure vessel) of diameter $30 \mathrm{~cm}$ and wall thickness $1 \mathrm{~mm}$ is subjected to a design maximum internal pressure of 5 bar $(0.5 \mathrm{MPa})$. The material used for manufacturing this cylinder has a failure stress of $260 M P a$. Assuming von Mises failure criterion, the factor of safety (with respect to maximum allowable stress) for this cylinder is
(A) 2.8
(B) 2.0
(C) 6.9
(D) 4.0
A gas cylinder (closed thin-walled cylindrical pressure vessel) of diameter $30 \mathrm{~cm}$ and wall thickness $1 \mathrm{~mm}$ is subjected to a design maximum internal pressure of 5 bar $(0.5 \mathrm{MPa})$. The material used for manufacturing this cylinder has a failure stress of $260 M P a$. Assuming von Mises failure criterion, the factor of safety (with respect to maximum allowable stress) for this cylinder is
(A) 2.8
(B) 2.0
(C) 6.9
(D) 4.0