As a gasoline engine is running, an amount of gasoline containing 15,000 J of chemical potential energy is burned in 1 s. During that second, the engine does 3,000 J of work.

(a) What is the engine’s efficiency?
(b) The burning gasoline has a temperature of about 4,000^oF (2,500 K). The waste heat from the engine flows into air at about 80^oF (300 K). What is the Carnot efficiency of a heat engine operating between these two temperatures?