ALTERNATIVE ENERGY SOURCES Because of the increasingly important role played by coal as a viable alternative energy source, the production of coal has been growing at the rate of 3.5e0.05t billion metric tons/year, t years from 1980 (which corre- sponds to t = 0). Had it not been for the energy crisis, the rate of production of coal since 1980 might have been only 3.5e0.011 billion metric tons/year, t years from 1980. Determine how much additional coal was produced between 1980 and 2000 as an alternative energy source.