Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2015-10-17 12:58:51

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Micro / Macro numbers in Science

Micro / Macro numbers in Physics and Chemistry :

Planck's Constant :

Last edited by Jai Ganesh (2015-10-17 15:09:27)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#2 2015-10-17 14:34:30

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Electron Rest Mass :

kilograms.
Mass of Neutron :
kilograms.
Mass of Proton :
kilograms.
Avagadro Constant :

Boltzmann Constant :

.

Charge of an Electon :


coulumbs.
Charge of a Proton :
coulumbs.

Last edited by Jai Ganesh (2015-10-27 12:11:25)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#3 2015-10-17 17:40:45

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Coulumbs per kilogram.
Mass of Earth
kilograms.
Mass of Sun
kilograms.
Age of Earth, Sun
years.

Last edited by Jai Ganesh (2015-10-19 15:50:47)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#4 2015-10-19 15:48:44

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Gravitational Constant

.

Last edited by Jai Ganesh (2015-10-26 19:53:28)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#5 2015-10-19 16:09:04

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Standard acceleration due to gravity, in vaccum

near of the surface of the earth.

Last edited by Jai Ganesh (2015-10-19 16:14:13)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#6 2015-10-19 16:41:58

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Micro / Macro numbers in Science

Please add speed of light, fine structure constant and gas constant too


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Offline

#7 2015-10-19 16:53:35

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Certainly, comrade... In a few hours...


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#8 2015-10-19 17:39:39

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Velocity of light :

.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#9 2015-10-19 17:57:18

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Fine structure constant : charectering the strangth of the electromagnetic interaction beween elementary charged particles also known as Sommerfeld's constant denoted by

is a fundamental physical constant charecterizing the strength of the electromagnetic interaction between the elementary charged particles. Value :
.

No unit.

Last edited by Jai Ganesh (2015-10-19 18:01:25)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#10 2015-10-19 18:05:17

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Gas constant :


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#11 2015-10-20 14:44:42

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Heaviest Metal : Osmium : Density :


Second Heaviest Metal : Iridium : Density :
.

Last edited by Jai Ganesh (2015-10-20 14:48:22)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#12 2015-10-20 15:17:30

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Lightest gas : Hydrogen : Density at STP : 0 degrees Centigrade and 101.325 kPa :


When liquid at melting point

Second lightest gas : Helium : Density at STP : at 0 degrees Centigrade and 101.525 kPa :


When liquid at Melting Point

Last edited by Jai Ganesh (2015-10-20 15:25:09)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#13 2015-10-23 11:55:57

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Planetary Data Distance Table
Planet     : Distance      (from Sun)         :    Diameter
Mercury     : 57,910,000 km :0.387 A.U.   : 4,800 km
Venus     : 108,200,000 km :  0.723 A.U. : 12,100 km
Earth     : 149,600,000 km :  1.000 A.U  : 12,750 km
Mars             : 227,940,000 km : 1.524 A.U.  : 6,800 km
Jupiter     : 778,330,000 km : 5.203 A.U.  : 142,800 km
Saturn        : 1,424,600,000 km : 9.523 A.U.: 120,660 km
Uranus      : 2,873,550,000 km: 19.208 A.U. : 51,800 km
Neptune       : 4,501,000,000 km :  30.087 A.U. : 49,500 km
Pluto      : 5,945,900,000 km : 39.746 A.U. :    3,300 km

Last edited by Jai Ganesh (2015-10-26 20:03:11)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#14 2015-10-23 14:07:29

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Helium gas has a density of 0.164g/liter It is 0.139 times as dense as air.
Air has a density of 1.18g/liter.

Material : Specific Gravity
Balsa wood : 0.2
Oak wood  : 0.75
Ethanol : 0.78
Water : 1
Table salt : 2.17
Aluminium: 2.7
Iron     : 7.87
Copper : 8.96
Lead     : 11.35
Mercury : 13.56
Depleted uranium : 19.1
Gold     : 19.3
Osmium : 22.59

(Samples may vary, and these figures are approximate.)   
Urine normally has a specific gravity between 1.003 and 1.035.
Blood normally has a specific gravity of ~1.060.


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#15 2015-10-23 14:58:56

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change. The SI unit of heat capacity is joule per kelvin

and the dimensional form is
. Specific heat is the amount of heat needed to raise the temperature of a certain mass 1 degree Celsius.

Last edited by Jai Ganesh (2015-10-23 15:11:04)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#16 2015-10-23 15:50:35

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Mass heat capacity of building materials


(Usually of interest to builders and solar designers)
Mass heat capacity of building materials Substance  : Phase : cP :


Asphalt : solid  : 0.920
Brick  : solid  : 0.840
Concrete :    solid : 0.880
Glass, silica : solid : 0.840
Glass, crown : solid : 0.670
Glass, flint : solid : 0.503
Glass, pyrex : solid : 0.753
Granite : solid :     0.790
Gypsum : solid  : 1.090
Marble, mica  : solid  : 0.880
Sand : solid : 0.835
Soil : solid :  0.800
Water : liquid  : 4.1813
Wood : solid : 1.7 (1.2 to 2.9)
Substance     : Phase  : cP :

Last edited by Jai Ganesh (2015-10-23 16:05:10)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#17 2015-10-23 20:40:28

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

In optics the refractive index or index of refraction n of an optical medium is a dimensionless number that describes how light, or any other radiation, propagates through that medium. It is defined as. where c is the speed of light in vacuum and v is the phase velocity of light in the medium.


Some representative refractive indices Material     :  λ (nm)     :  n    
Vacuum         : 1 (by definition)    
Air at STP         : 1.000277    
Gases at 0 °C and 1 atm
Air : 589.29     : 1.000293    
Carbon dioxide     : 589.29 : 1.00045    
Helium : 589.29     : 1.000036    
Hydrogen     589.29 : 1.000132    
Liquids at 20 °C
math trisulfide and sulfur in methylene iodide :    1.9    
Benzene : 589.29 : 1.501    
Carbon disulfide    :589.29 : 1.628    
Carbon tetrachloride :    589.29  : 1.461    
Ethanol (ethyl alcohol) : 589.29 : 1.361    
Silicone oil :     1.336-1.582    
Water : 589.29     : 1.3330    
10% Glucose solution in water :    589.29  :    1.3477    
20% Glucose solution in water :     589.29  :  1.3635    
60% Glucose solution in water :    589.29  : 1.4394    
Solids at room temperature
Titanium dioxide (rutile phase) :589.29 :  2.614    
Diamond :  589.29 :    2.419    
Strontium titanate  :    589.29 : 2.41    
Amber : 589.29     : 1.55    
Fused silica (also called fused quartz)     : 589.29 : 1.458    
Sodium chloride : 589.29 :     1.544    
Other materials
Liquid helium :    1.025    
Water ice     : 1.31    
Cornea (human) : 1.373/1.380/1.401    
Lens (human)      : 1.386 - 1.406    
Acetone         : 1.36    
Ethanol         : 1.36    
Glycerol         : 1.4729    
Bromine         : 1.661    
Polytetrafluoroethylene (Teflon AF) : 1.315    
Polytetrafluoroethylene (Teflon) :    1.35 - 1.38     :
Cytop         : 1.34    
Sylgard 184 (polydimethylsiloxane) : 1.4118    
Polylactic acid     :1.46    
Acrylic glass     : 1.490 - 1.492    
Polycarbonate     :    1.60    
Poly(methyl methacrylate) (PMMA) :    1.4893 - 1.4899    
PETg         : 1.57    
Polyethylene terephthalate (PET) : 1.5750    
Kerosene      : 1.39    
Crown glass (pure) :    1.50 - 1.54    
Flint glass (pure) :    1.60 - 1.62    
Crown glass (impure) : 1.485 - 1.755    
Flint glass (impure)     : 1.523 - 1.925    
Pyrex (a borosilicate glass)     : 1.470
Cryolite :     1.338    
Halite (rock salt) : 1.516    
Sapphire     : 1.762–1.778    
Sugar solution, 25% :     1.3723    
Sugar solution, 50%     : 1.4200    
Sugar solution, 75%     :    1.4774    
Cubic zirconia :    2.15 - 2.18    
Potassium niobate (KNbO3) : 2.28    
Silicon carbide (moissanite)     : 2.65 - 2.69    
Cinnabar (mercury sulfide)     : 3.02    
Gallium(III) phosphide : 3.5    
Gallium(III) math :3.927    
Zinc oxide : 390 : 2.4    
Germanium     3000 - 16000     4.05 - 4.01    
Silicon     1200 - 8500     3.48 - 3.42


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#18 2015-10-24 01:57:46

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Table of Specific Heats for Various Substances
Substance    
Air (50 degrees C) : 1046 : 0.250
Aluminum, Al :     900 :     0.215
Benzene, C6H6     : 1750  :    0.418
Copper, Cu :    387 :     0.0924
Glass     : 837 :    0.200
Gold, Au     : 130 : 0.0310
Ice, H2O (-10 degrees C to 0 degrees C) :    2093 :    0.500
Iron, Fe      : 452 : 0.108
Lead, Pb     : 128  : 0.0305
Marble     : 858 :    0.205
Methanol or methyl Alcohol, CH3OH : 2549     : 0.609
Mercury, Hg     : 138  : 0.0330
Silver, Ag     : 236 : 0.0564
Soil     : 1046 :    0.250
Steam, H2O (100 degrees C)  :2009 :    0.480
Water, H2O (0 degrees C to 100 degrees C)     : 4186 : 1.000
Wood     : 1674 :    0.400


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#19 2015-10-24 06:24:31

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 700 nm. In terms of frequency, this corresponds to a band in the vicinity of 430–770 THz.

Color     : Wavelength     : Frequency     : Photon energy
violet     : 380–450 nm     : 668–789 THz     : 2.75–3.26 eV
blue             : 450–495 nm     : 606–668 THz     : 2.50–2.75 eV
green        :495–570 nm    :526–606 THz     : 2.17–2.50 eV
yellow     : 570–590 nm     : 508–526 THz     : 2.10–2.17 eV
orange     : 590–620 nm     : 484–508 THz     : 2.00–2.10 eV
red             : 620–750 nm     : 400–484 THz     : 1.65–2.00 eV


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#20 2015-10-24 07:02:44

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Tables

In the standard atmosphere:

    T0 is 273.15 K (= 0 °C = 32 °F), giving a theoretical value of 331.3 m/s (= 1086.9 ft/s = 1193 km/h = 741.1 mph = 644.0 kn). Values ranging from 331.3-331.6 may be found in reference literature, however;
    T20 is 293.15 K (= 20 °C = 68 °F), giving a value of 343.2 m/s (= 1126.0 ft/s = 1236 km/h = 767.8 mph = 667.2 kn);
    T25 is 298.15 K (= 25 °C = 77 °F), giving a value of 346.1 m/s (= 1135.6 ft/s = 1246 km/h = 774.3 mph = 672.8 kn).

In fact, assuming an ideal gas, the speed of sound c depends on temperature only, not on the pressure or density (since these change in lockstep for a given temperature and cancel out). Air is almost an ideal gas. The temperature of the air varies with altitude, giving the following variations in the speed of sound using the standard atmosphere—actual conditions may vary.
Effect of temperature on properties of air Temperature
T (°C)     : Speed of sound
c (m/s)     : Density of air
ρ (kg/cubic meters)     : Characteristic specific acoustic impedance
z0 (Pa·s/m)
35      : 351.88     : 1.1455     : 403.2
30       : 349.02     : 1.1644     : 406.5
25       : 346.13     : 1.1839     : 409.4
20       : 343.21     : 1.2041     : 413.3
15       : 340.27  : 1.2250     : 416.9
10       : 337.31  : 1.2466     : 420.5
5       : 334.32      : 1.2690     : 424.3
0       : 331.30      : 1.2922     : 428.0
−5       : 328.25      : 1.3163     : 432.1
−10       : 325.18      : 1.3413     : 436.1
−15       : 322.07   : 1.3673     : 440.3
−20       : 318.94      : 1.3943     : 444.6
−25       : 315.77      : 1.4224     : 449.1

Last edited by Jai Ganesh (2015-10-26 20:19:08)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#21 2015-10-24 12:46:38

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

Modern classification

The modern classification system is known as the Morgan–Keenan (MK) classification. Each star is assigned a spectral class from the older Harvard spectral classification and a luminosity class using Roman numerals as explained below, forming the star's spectral type.

Harvard spectral classification

The Harvard classification system is a one-dimensional classification scheme using single letters of the alphabet, optionally with numeric subdivisions, to group stars according to their spectral characteristics. Main-sequence stars vary in surface temperature from approximately 2,000 to 50,000 K, whereas more-evolved stars can have temperatures above 100,000 K. Physically, the classes indicate the temperature of the star's atmosphere and are normally listed from hottest to coldest.
Class     Effective temperature     Conventional color description     Actual apparent color     Main-sequence mass
(solar masses)     Main-sequence radius
(solar radii)     Main-sequence luminosity
(bolometric)     Hydrogen
lines     Fraction of all
main-sequence stars

O     ≥ 30,000 K     blue     blue     ≥ 16 M☉     ≥ 6.6 R☉     ≥ 30,000 L☉     Weak     ~0.00003%
B     10,000–30,000 K  blue white     blue white     2.1–16 M☉     1.8–6.6 R☉     25–30,000 L☉     Medium     0.13%
A     7,500–10,000 K     white     blue white     1.4–2.1 M☉     1.4–1.8 R☉     5–25 L☉     Strong     0.6%
F     6,000–7,500 K     yellow white     white     1.04–1.4 M☉     1.15–1.4 R☉     1.5–5 L☉     Medium     3%
G     5,200–6,000 K     yellow     yellowish white     0.8–1.04 M☉     0.96–1.15 R☉     0.6–1.5 L☉     Weak     7.6%
K     3,700–5,200 K     orange  pale yellow orange     0.45–0.8 M☉     0.7–0.96 R     0.08–0.6 L☉ Very weak     12.1%
M     2,400–3,700 K     red     light orange red     0.08–0.45 M☉     ≤ 0.7 R☉     ≤ 0.08 L☉     Very weak     76.45%

The spectral classes O through M, as well as other more specialized classes discussed later, are subdivided by Arabic numerals (0–9), where 0 denotes the hottest stars of a given class. For example, A0 denotes the hottest stars in the A class and A9 denotes the coolest ones.

Fractional numbers are allowed; for example, the star Mu Normae is classified as O9.7. The Sun is classified as G2.

The solar mass (M☉) is a standard unit of mass in astronomy that is used to indicate the masses of other stars, as well as clusters, nebulae and galaxies. It is equal to the mass of the Sun, about two nonillion kilograms:

M☉ =

Solar radius is a unit of distance used to express the size of stars in astronomy equal to the current radius of the Sun:

The solar luminosity, L☉, is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars. It is defined in terms of the Sun's output. One solar luminosity is

, or
. This does not include the solar neutrino luminosity, which would add 0.023 L☉. The Sun is a weakly variable star, and its luminosity therefore fluctuates. The major fluctuation is the eleven-year solar cycle (sunspot cycle) that causes a periodic variation of about ±0.1%. Other variations over the last 200–300 years is thought to be much smaller than this.

Last edited by Jai Ganesh (2015-10-24 12:50:35)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#22 2015-10-24 16:38:46

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

The Sun in visible wavelength with filtered white light on 8 July 2014. Characteristic limb darkening and numerous sunspots are visible.
Observation data
Mean distance
from Earth    


8 min 19 s at light speed
Visual brightness (V)     -26.74
Absolute magnitude     4.83
Spectral classification     G2V
Metallicity     Z = 0.0122
Angular size     31.6–32.7′

Orbital characteristics
Mean distance from Milky Way core    


27200 light-years
Galactic period    
Julian Year (a)
Velocity    
(orbit around the center of the Milky Way)
≈ 20 km/s (relative to average velocity of other stars in stellar neighborhood)
≈ 370 km/s (relative to the cosmic microwave background)
Physical characteristics
Equatorial radius :
= 109 × Earth.
Equatorial circumference
= 109 × Earth
Flattening    

Surface area =
square kilometers.
12000 × Earth
Volume =
cubic kilometers = 1300000 × Earth
Mass =    
=
333000 × Earth
Average density     1.408 grams per cubic centimeters.
0.255 × Earth
Center density (modeled) = 162.2 grams per cubic centimeters = 12.4 × Earth
Equatorial surface gravity =
meters per second square = 27.94 g
27542.29 cgs
28 × Earth
Escape velocity = (from the surface)     617.7 km/s = 55 × Earth
Temperature     = Center (modeled):

Photosphere (effective): 5778 K
Corona:

Luminosity (Lsol) =


efficacy
Mean radiance (Isol)    
.
Age    
billion years
Rotation characteristics
Obliquity     7.25°
(to the ecliptic)
67.23°
(to the galactic plane)
Right ascension
of North pole     286.13°
19 h 4 min 30 s
Declination
of North pole     +63.87°
63° 52' North
Sidereal rotation period
(at equator)     25.05 days
(at 16° latitude)     25.38 days
25 d 9 h 7 min 12 s
(at poles)     34.4 days
Rotation velocity
(at equator)    

Photospheric composition (by mass)
Hydrogen     73.46%
Helium     24.85%
Oxygen     0.77%
Carbon     0.29%
Iron             0.16%
Neon     0.12%
Nitrogen     0.09%
Silicon     0.07%
Magnesium     0.05%
Sulfur     0.04%

Last edited by Jai Ganesh (2015-10-24 23:25:48)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#23 2015-10-25 01:39:40

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

The speed of sound is the distance travelled per unit time by a sound wave propagating through an elastic medium. The SI unit of speed is the metre per second (m/s). In dry air at 20 °C, the speed of sound is 343.2 metres per second (1,126 ft/s). This is 1,236 kilometres per hour (768 mph; 667 kn), or a kilometre in 2.914 s or a mile in 4.689 s.

Sir Isaac Newton computed the speed of sound in air as 979 feet per second (298 m/s), which is too low by about 15%, but had neglected the effect of fluctuating temperature; that was later rectified by Laplace.

During the 17th century, there were several attempts to measure the speed of sound accurately, including attempts by Marin Mersenne in 1630 (1,380 Parisian feet per second), Pierre Gassendi in 1635 (1,473 Parisian feet per second) and Robert Boyle (1,125 Parisian feet per second).

In 1709, the Reverend William Derham, Rector of Upminster, published a more accurate measure of the speed of sound, at 1,072 Parisian feet per second. Derham used a telescope from the tower of the church of St Laurence, Upminster to observe the flash of a distant shotgun being fired, and then measured the time until he heard the gunshot with a half second pendulum. Measurements were made of gunshots from a number of local landmarks, including North Ockendon church. The distance was known by triangulation, and thus the speed that the sound had travelled could be calculated.

Practical formula for dry air

The approximate speed of sound in dry (0% humidity) air, in meters per second, at temperatures near 0 °C, can be calculated from

   

,

where

is the temperature in degrees Celsius (°C).

In the standard atmosphere:

   

is 273.15 K (= 0 °C = 32 °F), giving a theoretical value of 331.3 m/s (= 1086.9 ft/s = 1193 km/h = 741.1 mph = 644.0 kn). Values ranging from 331.3-331.6 may be found in reference literature, however;
   
is 293.15 K (= 20 °C = 68 °F), giving a value of 343.2 m/s (= 1126.0 ft/s = 1236 km/h = 767.8 mph = 667.2 kn);
   
is 298.15 K (= 25 °C = 77 °F), giving a value of 346.1 m/s (= 1135.6 ft/s = 1246 km/h = 774.3 mph = 672.8 kn).

In fact, assuming an ideal gas, the speed of sound c depends on temperature only, not on the pressure or density (since these change in lockstep for a given temperature and cancel out). Air is almost an ideal gas. The temperature of the air varies with altitude, giving the following variations in the speed of sound using the standard atmosphere—actual conditions may vary.

Last edited by Jai Ganesh (2015-10-25 01:44:01)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#24 2015-10-25 07:03:56

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

table.gif


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

#25 2015-10-25 14:50:09

Jai Ganesh
Administrator
Registered: 2005-06-28
Posts: 45,955

Re: Micro / Macro numbers in Science

In SI units, thermal conductivity is measured in watts per meter kelvin

. The dimension of thermal conductivity is
. These variables are (M)mass, (L)length, (T)time, and (Θ)temperature. In Imperial units, thermal conductivity is measured in BTU/(hr·ft⋅°F).

Thermal Conductivity :  k : W/(m K)
Material/Substance :    Temperature :

25    125    225
Acetals     : 0.23    
Acetone     : 0.16        
Acetylene (gas) : 0.018        
Acrylic     : 0.2        
Air, atmosphere (gas) : 0.024        
Air, elevation 10000 m : 0.020        
Alcohol     : 0.17        
Aluminum     : 205     : 215     : 250
Aluminum Brass : 121        
Aluminum Oxide :30        
Ammonia (gas)     : 0.022        
Antimony     : .5        
Apple (85.6% moisture) :     0.39        
Argon (gas):  0.016        
Asbestos-cement board :    0.744        
Asbestos-cement sheets : 0.166        
Asbestos-cement : 2.07        
Asbestos, loosely packed :     0.15        
Asbestos mill board     : 0.14            
Asphalt     : 0.75        
Balsa wood : 0.048        
Bitumen     : 0.17        
Bitumen/felt layers :     0.5        
Beef, lean (78.9 % moisture) :     0.43 - 0.48        
Benzene     : 0.16        
Beryllium     : 218        
Bitumen     : 0.17        
Blast furnace gas (gas) :    0.02        
Brass     : 109        
Breeze block :     0.10 - 0.20        
Brick dense :1.31        
Brick, insulating : 0.15        
Brickwork, common (Building Brick)     : 0.6 -1.0        
Brickwork, dense : 1.6        
Bromine (gas)  : 0.004        
Bronze     : 110        
Butter (15% moisture content) :    0.20        
Cadmium     : 92        
Calcium silicate     : 0.05        
Carbon  : 1.7        
Carbon dioxide (gas) : 0.0146           
Carbon monoxide :    0.0232        
Cellulose, cotton, wood pulp and regenerated : 0.23        
Cellulose acetate, molded, sheet : 0.17 - 0.33        
Cellulose nitrate, celluloid :    0.12 - 0.21        
Cement, portland : 0.29        
Cement, mortar     : 1.73        
Chalk     : 0. 09           
Charcoal     : 0.2    
Chlorinated poly-ether :    0.13        
Chlorine (gas)     : 0.0081        
Chrome Nickel Steel (18% Cr, 8 % Ni)     : 16.3           
Chromium : 94        
Clay, dry to moist : 0.15 - 1.8           
Clay, saturated     : 0.6 - 2.5           
Coal     : 0.2        
Cobalt : 69        
Cod (83% moisture content) :     0.54        
Concrete, lightweight     : 0.1 - 0.3        
Concrete, medium  : 0.4 - 0.7        
Concrete, dense : 1.0 - 1.8        
Concrete, stone     : 1.7           
Constantan : 22        
Copper     :  401     : 400     : 398
Corian (ceramic filled) : 1.06        
Cork board     : 0.043        
Cork, re-granulated :     0.044        
Cork     : 0.07        
Cotton  :    0.04        
Cotton wool : 0.029        
Carbon Steel :     54 :    51 :    47
Cotton Wool insulation : 0.029        
Diamond     : 1000        
Diatomaceous earth (Sil-o-cel) : 0.06        
Diatomite : 0.12        
Earth, dry     : 1.5           
Engine Oil     : 0.15        
Ethane (gas) : 0.018        
Ether : 0.14        
Ethylene (gas) : 0.017        
Epoxy : 0.35        
Ethylene glycol     : 0.25        
Feathers     : 0.034        
Felt insulation : 0.04        
Fiberglass     : 0.04        
Fiber insulating board : 0.048        
Fiber hardboard     : 0.2           
Fire-clay brick
    1.4        
Fluorine (gas) : 0.0254        
Foam glass  : 0.045        
Freon R-12 (gas) :  0.007           
Freon R-12 (liquid) : 0.09        
Gasoline : 0.15        
Glass : 1.05        
Glass, Pearls, dry : 0.18        
Glass, Pearls, saturated : 0.76        
Glass, window : 0.96           
Glass, wool Insulation : 0.04        
Glycerol  : 0.28        
Gold     : 310  : 312  : 310
Granite  : 1.7 - 4.0        
Gravel : 0.7        
Ground or soil, very moist area :  1.4        
Ground or soil, moist area     : 1.0        
Ground or soil, dry area : 0.5        
Ground or soil, very dry area : 0.33        
Gypsum board     : 0.17        
Hairfelt  : 0.05           
Hardboard high density : 0.15        
Hardwoods (oak, maple..) : 0.16        
Helium (gas) : 0.142        
Honey (12.6% moisture content) : 0.5        
Hydrochloric acid (gas) : 0.013        
Hydrogen (gas)     : 0.168        
Hydrogen sulfide (gas) : 0.013        
Ice (0 degrees C, 32 degrees F)     : 2.18        
Insulation materials  : 0.035 - 0.16        
Iridium  : 147        
Iron     : 80     : 68 : 60
Iron, wrought : 59        
Iron, cast     : 55        
Kapok insulation : 0.034        
Kerosene     : 0.15        
Krypton (gas) : 0.0088        
Lead Pb : 35        
Leather, dry : 0.14        
Limestone     : 1.26 - 1.33        
Magnesia insulation (85%) :  0.07        
Magnesite     : 4.15           
Magnesium : 156        
Marble : 2.08 - 2.94        
Mercury, liquid : 8.3        
Methane (gas)  : 0.030        
Methanol     : 0.21        
Mica     : 0.71        
Milk     : 0.53         
Mineral wool insulation materials, wool blankets .. : 0.04           
Molybdenum :     138        
Monel     : 26        
Neon (gas)     : 0.046        
Neoprene     : 0.05        
Nickel     : 91        
Nitric oxide (gas) :     0.0238        
Nitrogen (gas)     : 0.024        
Nitrous oxide (gas)     :0.0151        
Nylon 6, Nylon 6/6 :    0.25        
Oil, machine lubricating SAE 50 :    0.15        
Olive oil     : 0.17        
Oxygen (gas) :    0.024        
Paper     : 0.05        
Paraffin Wax  : 0.25        
Perlite, atmospheric pressure :     0.031           
Perlite, vacuum     : 0.00137           
Phenolic cast resins     0.15        
Phenol-formaldehyde moulding compounds :    0.13 - 0.25        
Plaster light     : 0.2        
Plaster, metal lath : 0.47        
Plaster, sand     : 0.71        
Plaster, wood lath :    0.28        
Plasticine     : 0.65 - 0.8        
Plastics, foamed (insulation materials) : 0.03           
Platinum     : 70     : 71     72
Plutonium     : 6.7         :
Plywood     : 0.13        
Polycarbonate :    0.19        
Polyester     : 0.05        
Polyethylene low density, PEL : 0.33        
Polyethylene high density, PEH :     0.42 - 0.51        
Polyisoprene natural rubber : 0.13        
Polyisoprene hard rubber     : 0.16        
Polymethylmethacrylate : 0.17 - 0.25        
Polypropylene, PP : 0.1 - 0.22           
Polystyrene, expanded styrofoam : 0.03        
Polystyrol     : 0.043        
Polyurethane foam : 0.03        
Porcelain     : 1.5        
Potato, raw flesh : 0.55        
Propane (gas)     : 0.015        
Polytetrafluoroethylene, Teflon, PTFE :    0.25        
Polyvinylchloride, PVC : 0.19        
Pyrex glass     : 1.005        
Quartz mineral     : 3        
Radon (gas)     : 0.0033        
Rock, solid :     2 - 7           
Rock, porous volcanic (Tuff) : 0.5 - 2.5           
Rock Wool insulation :  0.045        
Rubber, cellular     : 0.045        
Rubber, natural     : 0.13        
Salmon (73% moisture content) : 0.50        
Sand, dry     : 0.15 - 0.25        
Sand, moist     : 0.25 - 2           
Sand, saturated :     2 - 4        
Sandstone :1.7           
Sawdust     : 0.08        
Sheep wool     : 0.039        
Silica aerogel     : 0.02           
Silicone cast resin : 0.15 - 0.32        
Silicone oil :0.1        
Silver     : 429        
Slag wool     : 0.042        
Slate     : 2.01        
Snow (temp <
C     0.05 - 0.25        
Sodium     : 135 (solid)     : 86 (liquid)    
Softwoods (fir, pine ..) : 0.12        
Soil, clay     : 1.1        
Soil, with organic matter :     0.15 - 2           
Soil, saturated :     0.6 - 4           
Steam, saturated : 0.0184        
Steam, low pressure     : 0.0188        
Steel, Carbon 1%     : 43        
Stainless Steel     : 16     : 17     : 19
Straw slab insulation, compressed : 0.09        
Styrofoam:      : 0.033        
Sulfur dioxide (gas) :     0.0086        
Sugars     : 0.087 - 0.22        
Teflon     : 0.25        
Timber     : 0.14        
Tin Sn     : 67        
Titanium     : 22        
Tungsten     : 174        
Uranium     : 27.6        
Urethane foam     : 0.021           
Vacuum :    0        
Vermiculite granules :     0.065           
Vinyl ester     : 0.25        
Water     : 0.58        
Water, vapor (steam) :        0.016    
Wheat flour :0.45        
Wood across the grain, white pine :     0.12        
Wood across the grain, balsa :    0.055        
Wood across the grain, yellow pine, timber : 0.147        
Wood, oak :    0.17           
Wool, felt :    0.07        
Wood wool, slab :     0.1 - 0.15        
Xenon (gas) :    0.0051        
Zinc Zn :    116

Last edited by Jai Ganesh (2015-10-27 15:54:04)


It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

Board footer

Powered by FluxBB