6.4 A cylindrical specimen of a nickel alloy having an elastic modulus of 207GPa(30106psi) and an original diameter of 10.2mm(0.40in.) experiences only elastic deformation when a tensile load of 8900N (2000 lb f ) is applied. Compute the maximum length of the specimen before deformation if the maximum allowable elongation is 0.25mm(0.010in.). 6.15 A cylindrical specimen of steel having a diameter of 15.2mm(0.60in.)andlengthof250 mm(10.0in.) is deformed elastically in tension with a force of 48,900N(11,000lbf). Using the data contained in Table 6.1, determine the following: (a) The amount by which this specimen will elongate in the direction of the applied stress. (b) The change in diameter of the specimen. Note: for steel, the value of Poisson's ratio, v, is 0.30. Will the diameter increase or decrease