Solve the following problem:
(a) The tension in a wire is increased quasi-statically and isothermally from to If the length, cross-sectional area, and isothermal Young's modulus of the wire remain practically constant, show that the work done is
W = L/2AY(ζ2f - ζ2i)
(b) The tension in a copper wire 1m long and 0.001 cm2 in area is increased quasistatically and isothermally at 20°C from 10 to 100 N. How much work is done if the isothermal Young's modulus at 20°C is 1.23 X 1011N/m2?