[Phys-l] Specific Heat Experiments (was Re: glassware needed)

["Marc \"Zeke\" Kossover" <zeke_kossover@yahoo.com>]

From: Brian Whatcott <betwys1@sbcglobal.net>

> Folks who want to make concrete some relations which may help student
> understanding might consider the virtues of hot pennies.
> Adding a hot penny at a time to a sample of cold water might well
> show off a staircase of temperature versus number.
>
> This is essentially your recommendation, John, but rendered concrete,
> with all its possibility of scorching juvenile skin, it's true!
> [What's so intuitive about an invisible pulse of electrical heating, anyway?]

It occurs to me that this would be an easy experiment to do.

Drill a small hole into a penny (or use washers). Tie on a bit of cotton thread. Immerse in boiling water with the thread over the side. You and I know that the boiling water maintains a constant temperature, but for the kiddies, just put in a thermometer for them to measure the initial temperature of the pennies.

Move them one at a time into your cup of water. You can even sort of stir them with the string. 

Of course, you can really get above boiling this way. I guess you could start with the pennies in hot oil. Messy and dangerous. Ick. But maybe you could heat them on a high thermal mass hotplate. You could do heat of fusion though. 

Aluminum washers are kind of pricey but you could use them to compare the amount of temperature increase per washer. In doing a search of specific heats of washers, I just learned something -- just about every metal has the same specific heat per mole. <http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/dulong.html#c1> 

I've got to give this a try.

Zeke Kossover