Question

"A continuous electric current of 2,000 amps is to be transmitted from a generator to a transformer located 200 feet away. A copper conductor can be installed for $5.8 per pound, will have an estimated life of 23 years, and can be salvaged for $0.8 per pound. Power loss from the conductor will be inversely proportional to the cross-sectional area of the conductor. The power loss in one hour may be expressed as 6.222/A kilowatt, where A is the cross-sectional area of the conductor in square inches. The cost of energy is $0.0781 per kilowatt-hour, the interest rate is 15%, and the density of copper is 555 pounds per cubic foot. Calculate the optimum cross-sectional area of the conductor. You should assume the conductor operates 24 hours a day, 365 days per year."