6. You are given a 3-bit full adder, and several 2-to-1 multiplexers. Suppose A is a 3-bit input number. Design a circuit that can perform the following operations based on a 2-bit control code S1 S0. Ignore any overflow problem. Show clearly how the control signals S1 and S0 are used. Make your design as simple as possible.

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.