Mathematics and Society - OS X Lion Server

SOURCES OF ENERGY FOR THE U.S.In 1850 In 1970 In 2000(estimated)Source Percent Source Percent Source PercentSun- --Fossil fuel Fossil fuelWood 64 Coal 20 Coal 16Food for work Petroleum 41 Petroleum 37animals 22 Natural gas 33 Natural gas 18Wind, water 7--SunSunFossil fuel Hydroelectricity 4 Hydroelectricity 3Coal 7Misc. Nuclear 26Nuclear, wood 2FROM: Energy Crises in Perspective and Statistical Abstract of the United States 19751) In 1850, what total percent of the energy carne from the sun?2) How does the total percent of the energy from fossil fuel in 1970 compare with thepercent in 2000?3) Does that mean we will use less fossil fuel in 2000 than in 1970?(Hint: Total U.S. energy used in 1970, 67.1 quadrillion units; in 2000, 191.9quadrillion units.)4) What percent of the 1970 total energy used is the 2000 total energy used? (Seeinformation in exercise 3.)5) What environmental problems does each of the sources involve: coal, petroleum,natural gas, hydroelectricity, nuclear?6) Which sources can't be replaced?Permission to use granted by John Wiley and Sons, Inc. 241