A composite plane wall consists of a 5-in.-thick layer of insulation (ks = 0.029 Btu/h*ft*°R) and a 0.75-in.-thick layer of siding (ks = 0.058 Btu/h*ft*°R). The inner temperature of the insulation is 67°F. The outer temperature of the siding is -8°F. Determine at steady state:

(a) the temperature at the interface of the two layers, in °F, and (b) the rate of heat transfer through the wall in Btu/h*ft^2 of surface area.

For a gate width of 2 m into the paper, determine the force required to hold the gate abc at its location.

An open feedwater heater operates at steady state with liquid entering at inlet 1 with t? = 40°c and pl = 1 .2 mpa. water vapor att2-200°c and p2 = 1.2 mpa enters at inlet 2. saturated liquid water exits with a pressure of pa 1.2 mpa. neglect heat transfer with the surroundings and all kinetic and potential energy effects, determine the mass flow rate of steam at inlet 2 if the mass flow rate of liquid water at inlet 1 is given as 2 kg/s.

The air in an automobile tire with a volume of 0.015 m3 is at 32°c and 140 kpa gage. determine the amount of air that must be added to raise the pressure to the recommended value of 206 kpa gage. assume the atmospheric pressure to be 128 kpa and the temperature and the volume to remain constant.[r-0.287 kj/kgk]