The center aluminum rod cd (ea = 70 gpa, αa = 23 × 10−6/°c) of the assembly is heated from 30°c to 180°c using electrical resistance heating and the temperature in the two identical steel rods ab and ef(es = 200 gpa, αs = 12 × 10−6/°c) rises from 30°c to 50°c. each steel rod has a cross sectional area of 125 mm2 and the cross sectional area of the aluminum rod is 375 mm2. if there is a 0.7-mm gap between rod cdand the rigid top block bf at 30°c, determine the normal stresses in the rods caused by the increase in temperature.

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?

Starting wih an energy balance on a rectangular volume element, derive the one- dimensional transient heat conduction equation for a plane wall with constant thermal conductivity and no heat generation.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.