Consider a hypothetical x+y− ion pair for which the equilibrium interionic spacing and bonding energy values are 0.38 nm and –5.37 ev, respectively. if it is known that n in equation 2.17 has a value of 8, using the results of problem 2.18, determine explicit expressions for attractive and repulsive energies ea and er of equations 2.9 and 2.11.
en = -a/r + b/(r^n)
calculate the bonding energy eo in terms of the parameters a, b and n.

The higher the astm grain size number, the finer the gran is. a)-true b)-false

True or false (explain) (110)[111] is a slip system in bcc metals . the {111} family in fcc contains 8 planes. resolved shear stress (rss) in single crystals is just related to the applied stress. critical resolved shear stress (crss) in single crystal metals is direct proportional to the number of defects in the structure

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.