Re: [Phys-l] Pound mass or weight?

[Brian Whatcott <betwys1@sbcglobal.net>]

At 07:08 AM 11/6/2008, Anthony L., you wrote:

> Our school gets reams of "Aspen 30" paper. On the outer cover are these
> numbers:
>
> 92 BRIGHT                       (What does this mean?)
> 20 lb.  75 gsm/10 M     (What does this mean?)
> 500 Sheets
> 8.5 x 11

This is the sort of question that is Platonic in its educational merit.
I found that the 20 lb, the 10M and the 75 gsm specifiers
are related in an idiosyncratic way.

For an American used to customary units, the 10M may be the
most intuitive:
the weight in pounds of a stack of 1000 sheets of the specified
size paper, in this case US letter size - 8.5 X 11 inches.

The 20 lb specifier is the weight of 500 sheets of the uncut sheet
of a customary size for a particular purpose: for US letter,
 the basis size is  22 X 17 inches, allowing a four way cut to
letter size.

For a European, the 75 grams mass per square meter of a
single sheet would be more intuitive I suppose, though it is
 abbreviated as gsm and referred to as density (!).
The 92 is apparently an objective spec for reflectance (%)

Test question: what does this Aspen 30 package weigh?


Brian Whatcott    Altus OK    Eureka!