2-3. A group of enterprising engineering students
has developed a process for extracting combustible
methane gas from cow manure (don’t worry, the
exhaust is orderless). With a specially adapted
internal combustion engine, the students claim that
an automobile can be propelled 15 miles per day from
the “cow gas” produced by a single cow. Their
experimental car can travel 60 miles per day for an
estimated cost of $5 (this is the allocated cost of
the methane process equipment—the cow manure is
essentially free). (2.1)