Heavy Air

[ChemEngrMBA]

inch and pounds are not metric ... don't most science nerds use metric units as measures for their science stuff?

I made this presentation to the lay public which is far more familiar with the English system than the metric system.
If you wish, feel free to make the conversion yourself.  Units don't change the weight or volume, do they?

I'm may (sic)be a moron, but I did have to endure two chemistry (+lab) classes and one physics (+lab) class.  We always used metric measures.

Nobody called you a moron. Such hateful attacks are standard fare for atheists and Democrats and I am neither of those.

Like meteorology ... when I was kid, barometric pressure was measured in inches of mercury, with 30 inches as a baseline at sea level ... now, the barometer readings are given in millibars ... I have to find a millibar-to-inches online calculator so my old brain can understand.

Exactly why I used English measures.

The real world is not a sterile laboratory with controlled conditions.  Real world measurements are more complex becaused the real world is not a controlled laboratory.  That's why much theoretical science stuff that works in a lab, goes sideways in the real world.

This was a simple brain exercise - nothing in any "controlled laboratory."  In the real world, air is heavier than most people imagine.
 It supports million pound airplanes, doesn't it.

For a nitwit, like myself, we need to explicity (sic) state the conditions of the test or experiment.  None of this "standard" this and "sea level" that and "pounds" stuff.

I specified 14.7 PSI, correcting my early error of 14.6.  Please forgive me for a one-tenth of a pound error.  I made things as simple as possible and all some people want to do is argue "humidity" and "dry air" and "pollution."  All irrelevant.
This horse is dead.  Stop beating it.

[Bigun]

@ChemEngrMBA

You are wasting your time with these people some of whom will argue about how many angels can dance on the head of a pin until the cows come home.

In the world I live in, Realville, the possibility of that single marble emerging by accident is so near zero that I'm going to call it impossible.

[Lando Lincoln]

@ChemEngrMBA

You are wasting your time with these people some of whom will argue about how many angels can dance on the head of a pin until the cows come home.

In the world I live in, Realville, the possibility of that single marble emerging by accident is so near zero that I'm going to call it impossible.

Back in the day, I derived a formula that accurately predicted/determined how many angels could dance on the head of a pin at any given moment given the type of music that was being played. I made no account for when the cows came home, however. I need to ruminate (get it?) on that variable.

[Bigun]

Back in the day, I derived a formula that accurately predicted/determined how many angels could dance on the head of a pin at any given moment given the type of music that was being played. I made no account for when the cows came home, however. I need to ruminate (get it?) on that variable.

ROFLMAO!!

[corbe]

   Couldn't this equation fit into the 'All Electrons striving for a lower Energy State' theory?

The Physics of Flame - What is Fire, Really?

Math and Science


118,129 views  Nov 25, 2024
In this video, we delve into the fascinating physics of fire and flame, exploring the underlying principles that make combustion possible. We start by examining the concept of activation energy, which is essential for initiating a fire. You’ll learn how this energy is needed to overcome the energy barrier for the chemical reactions involved in combustion.

Next, we explain how heat and light are produced during a fire. Discover the roles of exothermic reactions and the energy transformations that occur as fuel burns. We break down the combustion process into its key stages, from ignition to the production of flames and heat.

Through engaging visuals and detailed explanations, we’ll illustrate how different fuels and conditions affect the intensity and color of the flame. We also discuss the chemistry behind flame colors and how various elements influence them.

Join us for an in-depth look at the physics of fire, uncovering the science behind how fires start, sustain, and produce light and heat. Whether you’re a science enthusiast or just curious about how fire works, this video offers a thorough exploration of combustion and its effects.


https://www.youtube.com/watch?v=nfFtr877QDg

[Hoodat]

14.7 PSI - 12 PSI at 1 mile altitude times square inches in 1 square mile.
WHY do you insist on trying to look intelligent by bringing up things that are totally irrelevant?
"STP". Look it up.  Standard Temperature and Pressure.

I refer you back to the original question:

Now the question:

What is the mass of one cubic mile of air at sea level?

Assume STP, of course, and a perfect cube.  In other words, imagine a strong steel box 1 mile by 1 mile by 1 mile. 
If it were evacuated, sealed, and weighed at sea level, and then unsealed and air allowed to fill it, what is the increase over the tare weight?
The answer will astound you.

Since this question was first posted, there have been several inquiries on specifics and assumptions of the conditions.  For example, is the pressure uniform?  When you say to assume STP, then you are suggesting that pressure is to be considered uniform.  Yet your most recent assertion that the pressure at the top of the cube would be less than at the bottom suggests that it is not.  But if it is not, then is the median elevation at sea level?  Or is it the top of the cube that is at sea level as opposed to the bottom?

Also, which version of STP are we to use?  Scientific organizations define it differently.  Is standard pressure 1 bar?  Or is it 101,325 Pa?  Is standard temperature at 0°C, or is it at 25°C?  And then there's the composition of the air.  Saturated air weighs less than unsaturated air.  You would be better served by the members of this forum if you defined the question better.

There is also the matter of compressibility.  Air is not an ideal gas.  So compressibility would have to be factored in for the partial pressures of each component.

n = (PV) / ZRT


In the absence of said clarification, the following assumptions will be made:

Uniform pressure - 101.325 kPa
Standard Temp - 273.15 K  (zero water vapor pressure - dry air)
Universal gravity constant - 9.807 m/s²
MW of dry air ≈ 0.028965 kg/mol
Ideal Gas constant ≈ 8.3145 (m³ ⋅ Pa) / (K ⋅ mol)
Volume - 1 mi³ ≈ 4168181825 m³
Z ≈ 0.9994


n = [(101,325 Pa) * (4168181825 m³)] / [0.9994 * (8.3145 (m³ ⋅ Pa) / (K ⋅ mol)) * 273.15 K]

n = 1.861 E11 moles

mass = (1.861 E11 moles) * (0.028965 kg/mol) = 5,389,644,414 kg

US mass = 5389644414 kg * (0.06852 slugs/kg) = 369,308,000 slugs


This is roughly 14% higher than the answer you provided in Nov 2012 which is likely the result of the assumption I made about universal pressure throughout the cube and your assumption that the top of the cube was 1 mile above the ocean's surface.  If the cube sat along the dead sea, the top of the cube would be only ¾ miles above sea level, thus increasing the amount of air in the cube.  And if the cube rested on top of the Arctic ocean at the North Pole during low tide, it would be closer to the center of the earth making the acceleration of gravity greater.

Again, there have been legitimate questions asked regarding this problem.  Please extend the courtesy of explaining the rules.  Thanks.

[Hoodat]

   Couldn't this equation fit into the 'All Electrons striving for a lower Energy State' theory?

The Physics of Flame - What is Fire, Really?

Math and Science

Now I gotta go dig out my PChem textbook.  I have it on good authority though that Schrödinger's cat is indeed dead.

[verga]

Mass, or weight?  The two are not the same.  An object has the same mass on the Earth and the Moon (and anywhere else in the Universe for that matter), but that same object weighs only about 1/6th as much on the Moon as it does on the Earth.

Weight is the gravitational force acting on a given body—which differs depending on the gravitational pull of the opposing body (e.g. a person's weight on Earth vs on the Moon) — while mass is an intrinsic property of that body that never changes. In other words, an object's weight depends on its environment, while its mass does not.

Shh he is a chemical engineer with an MBA he knows everything. Well except for the difference between Mass and Weight.

[ChemEngrMBA]

Shh he is a chemical engineer with an MBA he knows everything. Well except for the difference between Mass and Weight.

Since you are so very clever, @verga, tell everyone the difference between one kilogram of mass and one kilogram of weight here on earth. 

_________________________________

Incidentally, Brilliant Creation 12: Fire - Page 100 of my book

[Hoodat]

Since you are so very clever, @verga, tell everyone the difference between one kilogram of mass and one kilogram of weight here on earth.

Where on earth?  A kilogram of mass will remain the same everywhere, even in outer space.  But the weight of that kilogram will depend on the forces acting upon it.  For example, it will weigh less at the equator than it will at the North Pole.   It will weigh less atop Mount Everest than it will in Death Valley.  Still a kilogram though.  Mass doesn't change.

[ChemEngrMBA]

The stalking underwear sniffer is on IGNORE

[corbe]

[verga]

Since you are so very clever, @verga, tell everyone the difference between one kilogram of mass and one kilogram of weight here on earth. 

_________________________________

Incidentally, Brilliant Creation 12: Fire - Page 100 of my book

I guess you were absent on the day they covered that in class. I will break this down for you a simply as I can. Mass is the total amount of material in an object. On the object weight is a function of how gravity acts on an object. If you have a cubic centimeter of lead the Mass will remain the same if you at sea level or or on the moon or say Mars. On the other hand the weight on the moon will be approximately 1/6th of it's weight on earth. Seriously if you don't understand something that simple, you might want to see about a refund on your degree. 

[Kamaji]

https://www.google.com/search?q=what+is+the+difference+between+mass+and+weight+on+earth

[bigheadfred]

There is no difference between a kilogram of mass and a kilogram of weight here on earth.

[Cyber Liberty]

There is no difference between a kilogram of mass and a kilogram of weight here on earth.

Here on Earth, at the equator, at sea level.  Go close to a pole, or elevate some, and they differ.  In the problem of the original post, we are to imagine a very high stack of air which inherently breaks the relationship between Mass and Weight.  It's why I won't play this game, and I'd rather have pie.

[bigheadfred]

Here on Earth, at the equator, at sea level.  Go close to a pole, or elevate some, and they differ.  In the problem of the original post, we are to imagine a very high stack of air which inherently breaks the relationship between Mass and Weight.  It's why I won't play this game, and I'd rather have pie.

The point I am trying to make is that one must assume the (query) is to be approached as a problem as it pertains to physics. That is not necessarily clear to a lay person.  In the more mundane world a kilogram is a kilogram is a kilogram.

[Hoodat]

Kilograms and pounds are not interchangeable.  They are measures of two different qualities.

Mass:  1 slug = 14.594 kg

Weight (force):  1 pound = 4.448 newtons

F = ma

[Cyber Liberty]

The point I am trying to make is that one must assume the (query) is to be approached as a problem as it pertains to physics. That is not necessarily clear to a lay person.  In the more mundane world a kilogram is a kilogram is a kilogram.

I can certainly agree with that!  I have not handled things outside of the standards set forth, so it is functionally the same thing.

[ChemEngrMBA]

I guess you were absent on the day they covered that in class. I will break this down for you a simply as I can. Mass is the total amount of material in an object. On the object weight is a function of how gravity acts on an object. If you have a cubic centimeter of lead the Mass will remain the same if you at sea level or or on the moon or say Mars. On the other hand the weight on the moon will be approximately 1/6th of it's (sic) weight on earth. Seriously if you don't understand something that simple, you might want to see about a refund on your degree.

"Moon" is your word, not mine.  I asked you to explain the "difference" between a kilogram of mass, on earth and a pound, on earth.
 You ignorantly bring up the moon, ignoring the patently obvious.  Seriously, you try to look smart and fail miserably.  The possessive form of "it" does not have a comma.  Seriously.

[ChemEngrMBA]

The point I am trying to make is that one must assume the (query) is to be approached as a problem as it pertains to physics. That is not necessarily clear to a lay person.  In the more mundane world a kilogram is a kilogram is a kilogram.

Your common sense should be recognized by @verga.  Well done Big Fred. @bigheadfred

[Hoodat]

"Moon" is your word, not mine.  I asked you to explain the "difference" between a kilogram of mass, on earth and a pound, on earth.

One is a measure of mass while the other is a measure of force.

[ChemEngrMBA]

https://www.google.com/search?q=what+is+the+difference+between+mass+and+weight+on+earth

Whoosh.  Right over so many heads simultaneously. 
THE POINT of my illustration is the massive WEIGHT of a cubic mile of air.   NOBODY ever guesses anything in excess of five million tons, weight/mass.
   
The most common answer I have heard is "Nothing.  Air weighs nothing."  If that were true, not even a hummingbird could fly, much less a 900,000 pound jetliner.

You people continue to beat a dead horse.  YOUR link says this:

 "Mass always stays the same, but weight can change depending on how much gravity is acting upon an object."

Please tell everyone "how much gravity is acting on the object" at sea level @Kamaji.

[Hoodat]

NOBODY ever guesses anything in excess of five million tons, weight/mass.

Is that short tons, or metric tons?

Please tell everyone "how much gravity is acting on the object" at sea level @Kamaji.

Sea level where?  At the North Pole, or at the Equator?

[ChemEngrMBA]

I guess you were absent on the day they covered that in class. I will break this down for you a simply as I can. Mass is the total amount of material in an object. On the object weight is a function of how gravity acts on an object. If you have a cubic centimeter of lead the Mass will remain the same if you at sea level or or on the moon or say Mars. On the other hand the weight on the moon will be approximately 1/6th of it's (sic) weight on earth. Seriously if you don't understand something that simple, you might want to see about a refund on your degree.

I just returned from a walk to the drug store, and on my walk, I considered the extremely ill-advised comments of @verga.
He never stops saying the silliest things!
Verga commingled the moon with earth, and lead with air.  Seriously, if you don't understand something that simple - air and earth - how can you possibly claim that something "will be approximately 1/6th of it's (sic) weight on earth"? 
The moon has no atmosphere, so any volume of air would instantly dissipate around the surface of the moon, wouldn't it, still slightly attracted by the moon's gravity.  Would that cubic mile still weigh 1/6th of it's (sic) weight on earth?

You might want to see someone about a refund on whatever educational paperwork you possess.
A person of character and honor would apologize for his foolhardiness.  I doubt that you will @verga.