Consider a cube of material of edge length 1 (initial volume is 1) loaded uniaxially by a stress o = 150 MPa. Young's modulus is E = 70 GPa, Poisson's ration is v = 0.3 and the yield stress is oy= 70 MPa. Compute the total volume change at o= 150 MPa. Note that the applied stress state is above the yield point.

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.