You are traveling in an airplane. The engineer who designed it is, casually, on your side. He tells you that the wings were designed using the Tresca criterion. Would you feel
safer if he had told you that the von Mises criterion had been used? Why?

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.

The power source in a certain welding setup generates 3500w that is transferred to the low carbon steel work with a heat transfer factor of 0.85. the melting factor in the operation is 0.45. a continuous fillet weld is to be made with a cross-sectional area of 23 mm2 determine the travel speed at which the welding can be accomplished.

Around steel bar, made from material with a yield stress of 750mpa, is loaded so that it has stresses co locations of maximum normal stress and maximum shear stress. use maximum shear stress and maximum distortion energy theories to calculate the safety factors for initial yielding failures.