Consider a large plane wall of thickness l 0.21 m, thermal conductivity k 2.5 w/m k, and surface area a 24 m2. the left side of the wall is subjected to a heat flux of 350 w/m2 while the temperature at that surface is measured to be 60 c assuming steady one-dimensional heat transfer, (a) obtain the finite difference formulation for the four nodes and b) determine the temperature of the wall by solving those equations

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.