If the beam is subjected to a shear of v = 30 kn, determine the web's shear stress at a and b. indicate the shear-stress components on a volume element located at these points. set w = 200 mm. show that the neutral axis is located at y = 0.2433 m from the bottom and i = 0.5382(10^-3) m^4. solve the problem for v = 50 kn instead of 30.

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.