mass density

Donald G. Shead wrote:


Take a look at air. Jiggle humidity, temp and pressure/altitude until
you get the magic 1 kg/m^3.

Why again does a SI unit need a natural analog with a ratio of 1?

In sci.math, Donald G. Shead
<[Only registered users see links. ]>
wrote
on 27 Apr 2004 05:25:52 -0700
<[Only registered users see links. ] >:

Actually, I lied. The units are not kg/m^3.
The units are N s^2/(m^4) or Pascal s^2 / m^2.
Basically, mass density is pressure times square seconds
divided by square meters.

(N = kg m/s/s so this works from a units standpoint. However,
most people would simply use kg/m^3.)

--
#191, [Only registered users see links. ]
It's still legal to go .sigless.

The Ghost In The Machine wrote:



Wait until he looks up how seconds: (The second is the duration of 9 192
631 770 periods of the radiation corresponding to the transition between
the two hyperfine levels of the ground state of the cesium 133 atom) and
meters: (The meter is the length of the path travelled by light in
vacuum during a time interval of 1/299 792 458 of a second)are defined.
That's going to complicate the search for the magic ratio of "1" almost
everywhere.

Sam Wormley <[Only registered users see links. ]> wrote in message news:<[Only registered users see links. ]>...

Don't you mean 'your mass' decreases, and that God is spiritual?

Colin <[Only registered users see links. ].nz> wrote in message news:<[Only registered users see links. ].nz >...

The sixth edition of AISC's manual of Steel Construction lists Air, at
0 degrees C, and 760 mm, pressure, as having a specific gravity of
1.0: With hydrogen being the lightest; @ 0.00599 pounds per cubic
foot.

TMG <[Only registered users see links. ]> wrote in message news:<[Only registered users see links. ]>...
Now there's a crock for you:

The quantity of matter [m] in any body or mass can be expressed as
various ratios:

[m] = w/vol. = f/a = ft/(s/t) = ft^2/s = w/g

Then, by ‘dimensional analysis'; we find from [m] = w/(vol), that w =
[m]/vol. and f = [m]/a = wa/g :: ... that

1 newton = 1newton x a/(9.81 m/sec^2) ... _NOT_ N = 1 kg·s-2!!!

"Donald G. Shead" wrote:

Your mass does decrease when you pee... and so does your volume. What is
important in this thread is that your density increases when you pee!

In article <[Only registered users see links. ]> ,
Donald G. Shead <[Only registered users see links. ]> wrote:

So if the temperature of the platinum rises, the platinum is less dense
than it was before. Density is still kg/m^3, except there's more m^3 in
the denominator.

I feel like you wanted to make some point besides that density changes
with temperature.


Why does anything have to have units of one kg/m^3?


--
"We don't grow up hearing stories around the camp fire anymore about
cultural figures. Instead we get them from books, TV or movies, so the
characters that today provide us a common language are corporate
creatures" -- Rebecca Tushnet

On 28 Apr 2004 05:46:01 -0700, [Only registered users see links. ] (Donald G. Shead)
wrote:


Oh, same as the specific gravity of water! Good, Donald.

But what does it tell us about the density of air, in real units of
density?



On Earth, of course, that would be somewhere between 0.00596 lbf/ft³
and 0.00602 lbf/ft³, then you need to multiply by whatever the
conversion factor is between normal pounds force that other people use
and Dense Donny pounds force to get your favorite units for this
quantity, Donald.

Gene Nygaard
[Only registered users see links. ]
Gentlemen of the jury, Chicolini here may look like an idiot,
and sound like an idiot, but don't let that fool you: He
really is an idiot.
Groucho Marx

"Donald G. Shead" wrote:


Some Densities sorted by Material Density
Category Material Density (g/cc)
-------- --------------- --------------
Wood Cherry 0.433
Wood Walnut 0.593
Wood Southern Pine 0.65
Wood Red Oak 0.673
Wood Sugar Maple 0.689
Wood Birch 0.705
Wood Mahogony 0.705
Chemical Gasoline 0.721
Chemical Benzene 0.737
Liquid Ethyl Alcohol 0.802
Liquid Methyl Alcohol 0.809
Other Ice 0.897
Liquid Water, Ice 0.897
Other Paraffin 0.898
Liquid Mineral Oil 0.914
Other Paper 0.929
Liquid Vegetable Oil 0.93
Other Leather, common 0.945
Plastic HDPE 0.955
Liquid Water, 100 °C 0.9581
Liquid Water, 4 °C 0.99997
Plastic Polyurethane 1
Liquid Seawater 1.025
Liquid Water, Seawater 1.025
Mineral Coal, Coke 1.201
Mineral Coal, Lignite 1.25
Mineral Coal, Bituminous 1.346
Plastic Kevlar 29 1.44
Plastic Kevlar 49 1.44
Plastic Kevlar 149 1.47
Plastic Rubber 1.506
Mineral Coal, Anthracite 1.554
Composite Carbon-Carbon Composite 1.65
Metal Magnesium, Pure 1.7
Metal Beryllium 1.8477
Metal Beryllium, QMV 1.85
Ceramic Graphite 2.163
Ceramic Quartz Glass 2.2
Ceramic Borosilicate Glass 2.3
Ceramic Boron Carbide 2.5
Ceramic Nitride-Bonded SiC 2.54
Ceramic Refrax 2.54
Ceramic SNBSN / "Refrax" 2.54
Ceramic Aluminosilicate 2.6
Ceramic Glass 2.6
Metal Aluminum 2.643
Metal Aluminum, 6061-T6 2.7
Metal Aluminum, 7079-T6 2.74
Ceramic Iron Slag 2.755
Metal Aluminum, 2024-T3 2.77
Ceramic Lead Glass 2.8
Ceramic Mullite 2.82
Ceramic BeO 2.85
Ceramic RB-SiC 3.09
Ceramic Sintered SiC 3.1
Ceramic Silicon carbide 3.2
Ceramic Aluminum Nitride 3.25
Ceramic Silicon Nitride 3.28
Ceramic SiAlON 3.3
Ceramic Alanx CG896 3.32
Ceramic Alumina, 85% 3.41
Ceramic Alumina, 90% 3.6
Ceramic Alumina, 94% 3.7
Ceramic Alumina, 96% 3.75
Mineral Iron Ore, Limonite 3.796
Ceramic Alumina, 99.5% 3.89
Ceramic Alumina 3.9
Ceramic Alumina, 99% 3.9
Ceramic Alumina, 99.9% 3.96
Mineral Corundum-Crystal Form 3.99
Ceramic Sapphire 3.99
Mineral Zinc Ore, blende 4.052
Ceramic ZTA 4.1
Mineral Manganese Ore 4.149
Mineral Pyrolusite, Mn Ore 4.149
Mineral Copper Ore, pyrites 4.197
Metal Titanium 4.5
Metal Titanium, B 120VCA 4.85
Ceramic TiC 4.94
Mineral Iron Ore, Magnetite 5.046
Mineral Iron Ore, Hematite 5.206
Ceramic Vanadium Carbide 5.71
Ceramic Mg-PSZ 5.75
Ceramic PSZ 5.75
Ceramic Zirconia 5.75
Ceramic Y-TZP 6.1
Metal Zirconium 6.3798
Ceramic Zirconium Carbide 6.56
Mineral Tin Ore, cassiterite 6.695
Metal Iron, Ferrosilicon 6.984
Metal Zinc, Cast 7.049
Metal Iron, grey cast 7.079
Metal Iron, Cast, Pig 7.207
Metal Pig Iron 7.207
Metal Tin, cast-hammered 7.352
Mineral Lead Ore, Galena 7.449
Metal Stainless 27Cr 7.47
Metal Iron, Spiegeleisen 7.496
Metal Manganese 7.608
Metal Iron, wrought 7.658
Metal Aluminum bronze 7.702
Metal Bronze, aluminum 7.702
Metal Steel, tool 7.715
Metal Wrought Iron 7.75
Metal Carbon Tool Steel 7.82
Metal Steel, cold-drawn 7.83
Metal Carbon Steel 7.84
Metal Steel, C1020, HR 7.85
Metal Pure Iron 7.86
Metal Soft Steel (0.06% C) 7.87
Metal Stainless 18Cr-8Ni 8.03
Metal Stainless Steel, 304 8.03
Metal Bronze, ~11% Tin 8.1
Metal Brass 8.553
Metal German Silver 8.586
Metal Nickel 8.602
Metal Monel Metal, rolled 8.688
Metal High Speed Tool Steel 8.75
Metal Bronze, phosphor 8.8
Metal Cobalt 8.8
Metal Copper, Pure 8.9
Metal Nickel, Pure 8.9
Metal Copper, cast-rolled 8.906
Metal Molybdenum, wrought 10.3
Metal Silver, Pure 10.5
Metal Silver, Cast-hammered 10.51
Metal Lead 11.37
Metal Thorium, Ind. melted 11.6
Ceramic Hafnium Carbide 12.76
Metal Mercury 13.57
Ceramic Tungsten Carbide 15.7
Ceramic WC / Tungsten Carbide 15.7
Metal Tantalum 16.6
Metal Gold Coin (US) 17.19
Metal Uranium 18.74
Metal Tungsten 18.82
Metal Uranium D38 18.97
Metal Gold, cast-hammered 19.3
Metal Gold, Pure 19.32
Metal Plutonium, alpha phase 19.35
Metal Platinum 21.3
Metal Iridium 22.16