Ahollow sphere of diameter 3 in. is filled with air at 200 atm, 60°f. the shell of the sphere has a mass of 0.2 lbm and is of negligible thickness. if the sphere is submerged in water at 60° f, determine the magnitude of the net vertical force, in lbf. is the force acting upward or downward? assume the air can be modeled as in ideal gas.

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