Re: [Phys-l] heat labs?

[Ludwik Kowalski <kowalskil@mail.montclair.edu>]

On Aug 24, 2007, at 2:45 PM, Ludwik Kowalski wrote:

> Suppose a metallic cup contains 250 cc of water. The initial
> temperature is 95 C. Students measure temperature every 5 minutes and
> calculate the remaining amount of thermal energy in water.

It would be better to say "and calculate changes in thermal energy of 
water."

> That will
> give the rates at which thermal energy is lost by water. Then ask them
> to repeat the experiment after the cup is surrounded by a layer of
> styrofoam tape.

What I had in mind was a flexible layer of foamy material (available in 
stores) tightly wrapped by a tape or string.

> Or use a simple two-cup calorimeter, first without and
> then with the outer cup. How is the rate of energy loss affected by a
> layer of insulation? Add something more challenging, if this is too
> simple. For example, measuring gradient of water temperature; I expect
> it to be measurably lower in the second case.
_______________________________________________________
Ludwik Kowalski, a retired physicist
5 Horizon Road, apt. 2702, Fort Lee, NJ, 07024, USA
Also an amateur journalist at http://csam.montclair.edu/~kowalski/cf/