2. Compatibility Determine the normal stress in the left wire A if the strain in the wire B is equal to 0.006. Load P causes the wires to be displaced vertically. (E in both wires is equal to 100 ksi and lA = √ 3lB). (Hint: This problem cannot be solved directly by equilibrium. you need to find a geometric relation between displacements in the wires)

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.