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.

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)