Some aircraft component is fabricated from an aluminum alloy that has a plane strain fracture toughness
of 35 mpa m (31.9 ksi in. ). it has been determined that fracture results at a stress of 250 mpa (36,250 psi)
when the maximum (or critical) internal crack length is 2.0 mm (0.08 for this same component and alloy, will
fracture occur at a stress level of 325 mpa (47,125 psi) when the maximum internal crack length is 1.0 mm (0.04
why or why not?

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.