Jim Elwell wrote:
....
> As to the different types of power (and energy), I give them (rounded)
> conversion factors for a variety of units, and 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 if it were
> peanut butter. Using such crazy comparisons helps them grasp that energy is
> energy in whatever form.
I like your demo, Jim!
I've also done what you suggest above and they manage it on an
intellectual level, but they still have this "gut" feeling that things
are different. Perhaps it's only a matter of the time needed for
knowledge to sink from the head to the belly. I used a problem a year
ago where they had to calculate the cost of the energy in a candy bar,
purchased at electrical company rates. The exams included many correct
answers but a few had comments indicating that "joules of food or
chemical energy were only analogous to joules of electrical energy". I
don't know; maybe they were trying too hard to picture "eating
electricity". I have since talked more about energy conversion
processes, such as burning candy bars to boil water to make steam to
drive a turbine to make electricity and that seems to help.
Jim
--
Metric Methods(SM) "Don't be late to metricate!"
James R. Frysinger, CAMS http://www.metricmethods.com/
10 Captiva Row e-mail: [EMAIL PROTECTED]
Charleston, SC 29407 phone/FAX: 843.225.6789
