At 12:15 PM 3/7/2002 -0600, Gene Mechtly wrote: >On Thu, 7 Mar 2002, Jim Elwell wrote: > > ... have them figure out how long a Twinkie will "power" a car, > > or how long a battery would "feed" a human, or how much the natural gas > > a house uses in a month would [be] if it were peanut butter.... > >I would omit the preliminary chore of having the students apply conversion >factors, but rather quote immediately the values of J/kg or J/g and the >mass of each specimen as an energy source. > >Students in all other countries and future US students would not have >the burden of non-SI source data, and have to make conversions from ifp.
I understand your thinking here, Gene, and I know others on this list would agree with you. However, my feeling is that I teach US citizens in the US, and they are going to have to deal with food in calories, electricity in kilowatthours and natural gas in dekatherms for a while yet, so I think they should know how to get from colloquial units to metric units. Said another way: a few months after they take my class and get their certificate, they will not remember all the conversions. However, they will remember how to do them and will know where to find the factors, should they ever need them in the future. Jim Elwell
