A cylindrical metal specimen 15.0mm in diameter and 150mm long is to be subjected to a tensile stress of 50 MPa; at this stress level the resulting deformation will be totally elastic. a. If the elongation must be less than 0.072mm which of the metals in the Table are suitable candidates? Why? b. If the maximum permissible diameter decrease is 0.0023 mm when the tensile stress of 50 MPa is applied, which of the metals that satisfy the criterion in part (a) are suitable candidates?

Table 6.1 Room-Temperature Elastic and Shear Moduli, and Poisson's Ratio for Various Metal Alloys