Klarinet Archive - Posting 000110.txt from 1995/08
From: "Chan, Jeff" <jeff.chan@-----.COM>
Subj: Re: Density v. Specific Gravity (Your Mail)
Date: Mon, 7 Aug 1995 20:12:00 -0400
> > On Aug. 5, 1995, BC wrote:
> >
> > >The density of normal grenadilla wood is apparently 1.3
> > >The density of the new Green line is about 1.4
> > >
> > >This is information directly from Buffet with whom i spoke recently,
> > >however, not being that familiar with density measurements, i can only
> > >guess that this is grams per/ ?
> > >per something
> >
> > (the rest snipped)
> >
> > The density numbers indicate the mass of the material in relationship to
> > that of water, i.e., normal grenadilla wood is 1.3 times the weight of the
> >
> > same volume of water; the green line "wood", 1.4. Therefore, the green
> > line is 1.08 times as heavy as normal grenadilla wood.
> >
> > Jeff Chan
> > Jeff.Chan@-----.com -- "freelance chamber music specialist" > >
>
> The above answer is correct; however, the units you're thinking of are
> grams per cubic centimeter (or milliliter). The original definition of
> the gram was the weight of one cubic centimeter of pure water at 4
> degrees Celsius, where water is at its densest. (In general, all
> materials shrink when cooled and expand when heated. Water is an
> exception; it expands when cooled from 4 degrees to 0 degrees Celsius.
> The reason has to do with the rather open crystalline structure of
> ice.)
>
> So the density of water is, by definition, exactly 1 gram per cubic
> centimeter at 4 degrees Celsius. Specific gravity is actually the
> quantity which Jeff refers to above, namely the ratio of the substance in
> question as compared to water. (This number, being a ratio, is a
> dimensionless quantity; it has no units.) The numbers
> are the same; it depends on how picky you want to get about the units.
>
> Laura Bornhoeft
Laura is, of course, correct. And I should know better, since my "day
job" is in mechanical engineering. The correction is appreciated.
Jeff Chan
Jeff.Chan@-----.com
