The column is constructed from high-strength concrete and eight A992 steel reinforcing bars. If the column is subjected to an axial force of 200 kip. a) Determine the average normal stress in the concrete and in each bar. Each bar has a diameter of 1 in.
b) Determine the required diameter of each bar so that 60% of the axial force is carried by concrete.

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.