As a gasoline engine is running, an amount of gasoline containing 11,700 J of chemical potential energy is burned in 1 5. During that second, the engine does 3,900 J of work. (a) What is the engine's efficiency (in percent)? (b) The burning gasoline has a temperature of about 4,300F (2,600 K). The waste heat from the engine flows into air at about 82F (301 K). What is the Carnot efficiency (in percent) of a heat engine operating between these two temperatures