The price of the equipment with installation is $12,000 for producing fresh water of 8,000 gal per day and that of electricity is $80/mwh. what is the cost of 1000 gal of fresh water production if (i) the annual fixed charge rate (fcr) together with the maintenance cost is 20% of the capital equipment price and (ii) the system efficiency (electrical energy to mechanical energy conversion) is 80%?

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?