A compound tube consists of a steel tube 140 mm internal diameter and 160 mm external diameter and an outer brass
tube 160 mm internal diameter and 180 mm external diameter.
The two tubes are of the same length. The compound tube
carries an axial load of 900 kN. Find the stresses and load
carried by each tube and the amount it shortens. Length of
each tube is 140 mm. Es = 2 × 105 N/mm2 and Eb = 1 × 105
N/mm2
.

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.