Acylindrical specimen of some metal alloy 10 mm (0.4 in.) in diameter is stressed elastically in tension. a force of 15,000 n (3370 lbf) produces a reduction in specimen diameter of 7 x 10 ^-3 mm (2.8 x 10^-4 compute poisson’s ratio for this material if its elastic modulus is 100 gpa ( 14.5 x 10^6 psi).

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.