Dear Harry and Matthew,

Thanks for the reminder, Harry.

I used to do a demonstration that involved a post office (equal arm) type
balance, a litre soft drink bottle of water, a one kilogram mass, and a
Perspex cube that I had made with 100 mm internal length width and height.

The steps went like this:
1   Show that the balance balanced.
2   Place the empty Perspex cube on one side of the balance, and use some
small masses to rebalance for the empty container.
3   Add the 1 kg mass to the other side � you could use butter or flour for
this, but make it into a real kilogram before the event.
4   Pour water from the one litre bottle of water, pausing occasionally for
dramatic effect � and pausing more often for dramatic effect as you reach
the last few drops in the bottle � and the top of the container.

This can be a very powerful demonstration with the only problem being to
make sure that you practice it a few times, and that you carefully measure
the amount of water in the bottle before the event � I used to place a
discreet mark on the bottle at a measured one litre level so that I could
refill the bottle (nonchalantly), if a repeat performance was required � as
it often was.

Cheers,

Pat Naughtin LCAMS
Geelong, Australia

Pat Naughtin is the editor of the free online newsletter, 'Metrication
matters'. You can subscribe by sending an email containing the words
subscribe Metrication matters to [EMAIL PROTECTED]
--

on 4/11/03 5:10 AM, Harry Wyeth at [EMAIL PROTECTED] wrote:

> Matthew,
> 
> The very best way to demonstrate the "feel" of a kilogram is to show a liter
> water bottle, filled with water! Explain the beauty of the connection between
> the two.
> 
> HARRY WYETH
> 

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