Electrical strain gauges were applied to a notched specimen to determine the stresses in the notch. the results were εx=0.0019 and εy=0.00072. find σx and σy if the material is made of carbon steel where e=200gpa, sy=360 mpa.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

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.