A cylindrical metal specimen 12.7 mm (0.5 in.) in diameter and 250 mm (10 in.) long is to be subjected to a tensile stress of 28 MPa (4000 psi); at this stress level, the resulting deformation will be totally elastic. a. If the elongation must be less than 0.080 mm (3.2 x 10^-3 in.), which of the metals are suitable candidates? Why?
b. If, in addition, the maximum permissible diameter decrease is 1.2 x 10^ -3 mm (4.7 x 10^-5 in.) when the tensile stress of 28 MPa is applied, which of the metals that satisfy the criterion in part (a) are suitable candidates? Why?