(a) Show, for a tensile test, that if there is no change

(a) Show, for a tensile test, that

if there is no change in specimen volume during the deformation process (i.e., A0l0 = Adld).
(b) Using the result of part (a), compute the percent cold work experienced by naval brass (the stress-strain behavior of which is shown in Figure 6.12) when a stress of 400MPa (58,000psi) isapplied.