Re: [Phys-l] heat labs?

[Brian Whatcott <betwys1@sbcglobal.net>]

At 01:19 PM 8/24/2007, you wrote:

> As our school year begins, I am looking for a good lab to do for my HEAT
> topic. I teach physics in HIGH SCHOOL, and all of my labs are LOW TECH.
> I've had some difficulty finding good labs to perform that are different
> from the ones typically done in chemistry:
>
> heat ice to boiling, then make a phase diagram
> determine the specific heat of a metal
>
> I don't want the labs to be too easy, like mixing hot/cold water and
> predict final temperature.

Three demonstrations that appeal to me:

Fix a metal rod or tube at one end, and rest the other end over a smooth
 surface, on which a sewing needle can roll.
Attach a paper pointer to the needle's eye, and rest the rod on the needle
 in the axis that allows the needle to roll when the rod expands.
Apply a Bunsen flame to the rod. Watch the expansion.
This can be made somewhat quantitative.

Place two squares of material in a deep freeze: one square of polystyrene
 foam   and one square of aluminum.
Place two such squares in an oven set to 120 degrees F.
Ask a student to evaluate the temperature of each square from the same
environment.      Qualititative but wonderfully touchy-feely.

Place two material samples of similar mass but widely different specific heat
in  known masses of water, consecutively.
All start temperatures are measured. Predict the
final stabilized temperature, for each material added seperately.


Brian Whatcott    Altus OK    Eureka!