6. The country of Eldorado, population 34 million, area 160,000 sq miles, enjoys fossil fuel resources equivalent to 100 billion barrels of crude oil. Currently, Eldorado's per capita energy use, all from fossil fuel resources, is equivalent to 30 barrels/year. Assume 0.000% population change. Eldoradoans wish to make their resources last 200 years. To achieve this goal they are implementing series of energy austerity measures. These measures are anticipated to result in an annual energy-use-reduction of r % every year for the 20 following years. The use will remain constant thereafter. Determine r such that the resources do last 200 years. a. b. An alternative plan calls for extending the resources' lifetime even further by shifting some of the use to renewable sources, in addition to the 20-year energy-use-reduction regime. The plan calls for installing 2000 wind turbines every year, for a period of 40 years, starting at year 11. Each turbine will generate an average of 4.3 million kWh a year. Assuming an annual usage reduction rate of 4.25% in years one through 20, how long will the fossil fuel resources last? Assume 6.10 x 10° J as the inherent energy in one barrel of crude oil.