Problem 2: Durability versus efficiency improvements in newer products In minimizing the environmental footprints of products, there is a tension between product durability and rapidly replacing older products with newer

products that have less environmental impact associated with their use. Consider the question - when is it most energy efficient to replace my vehicle? a. The production of a 1995 vehicle consumed 125,000 MJ of energy, and that the energy intensity of the materials used in manufacturing automobiles (energy required per kg of material) decreases by 1-2% per year. Assuming that the energy intensity of automobile manufacturing decreased by 1.5% per year between 1990 and 2010, calculate the energy required to produce a new automobile during the model years 1990, 2000, 2005 and 2010.(What mathematical equation takes into a percent change each year, based on each previous year?) b. The projected average fuel economy of light-duty automobiles is expected to increase from27.5 to 32.5 miles/gallon (or mpg) between 1990 and 2020. Assume that this increase occurs in step changes, with an average fuel economy of 27.5 mpg between 1990 and 1999,30 mpg between 2000 and 2009, and 32.5 mpg between 2010 and 2019.