In an ionically bonded solid the force between two ions is given by: F= b/r^2 - c/r^10

where r is the distance between the ions, b and care constants where b= 1.2x10^-28 Nm^2 and c= 1.8x10^-105 Nm^10.

Required:
a. Identify the attractive and repulsive terms in the expression.
b. Determine the ion separation in Å in the solid.
c. Determine the energy in eV required to separate the ions in the solid to an infinite distance apart.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

Carbon dioxide gas expands isotherm a turbine from 1 mpa, 500 k at 200 kpa. assuming the ideal gas model and neglecting the kinetic and potential energies, determine the change in entropy, heat transfer and work for each kilogram of co2.

An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0