Suppose a hollowed cylinder is made from an aluminum alloy that has the following properties: S(u) = 600 MPa, S(y) = 500 MPa, K(Ic) = 30 MPa-m1/2, r(i) = 9.0 cm and r(o) = 10.0 cm. The inner surface of the cylinder is to be pressurized while the outer surface is not. (The letters in parathesis are suppose to be subscripts). a) what value of internal pressure would cause the cylinder to fracture (in the absense of any initial crack?)