If M = 9.0 kip-ft, find the magnitude of the bending stress at a point 2.94 in. above the bottom surface of the beam. The moment of inertia about the z axis is 124.9 in.4, and the centroid of the section is located 4.7 in. above the bottom surface of the beam.

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.