Calcium oxide, crystallizes in the rock salt structureand the ionic radii of ca2+and o2-are 0.100 and 0.140 nm, respectively. if an externally applied electricfield results in a 5% expansion of the lattice, determine the dipole moment for each ca2+and o2-dipole pair. assume, that the material is unpolarized in the absence of an electric field.

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.