The wall of a rocket nozzle is of thickness L = 25 mm and is made from a high alloy steel for which  = 8000 kg/m3, c = 500 J/kgK and k = 25 W/m. K. During a test firing, the wall is initially at Ti = 25C and its inner surface is exposed to hot combustion gases for which h = 500 W/m2.K and T = 1750C. The outer surface is well insulated.

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.