This is a stupid question..
Safety Car
Joined: Apr 2004
Posts: 4,978
Likes: 1
From: MI
Originally Posted by vectorz
Do wheels weigh the same full of air, as they do without air?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
I'll admit, I didn't know the answer.
Drifting
Joined: Dec 2004
Posts: 1,820
Likes: 2
From: San Diego
---> My answer: Depends if you replaced the Winter air with Spring, or Summer air. 
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
Last edited by rickko; Jun 17, 2005 at 10:14 AM.
Instructor
Joined: Mar 2005
Posts: 136
Likes: 0
From: Mission Viejo CA
Originally Posted by michach1
The air weighs the same whether its in the tire or in the box. Pressurized air doesn't affect the air density. Density of air is only 2.7 lb per cubic meter!
Melting Slicks
Joined: Feb 2001
Posts: 2,114
Likes: 51
From: How the hell can I make it faster???
Originally Posted by rickko
---> My answer: Depends if you replaced the Winter air with Spring, or Summer air.
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
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Melting Slicks
Joined: Dec 2004
Posts: 3,049
Likes: 0
From: The second childhood is the best one of all.
Originally Posted by vectorz
Do wheels weigh the same full of air, as they do without air?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
Sorry. I just had to do that.
Race Director
Joined: Apr 1999
Posts: 15,148
Likes: 477
From: NM
Originally Posted by rickko
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
I don't see how air in a bottle would have any effect on a set of scales. The air without the bottle does not have any effect. So why would adding the bottle make any difference. No if you put double the amount of air in the bottle, then you would increase the weight.
Melting Slicks
Joined: Mar 2005
Posts: 2,439
Likes: 0
From: Phoenix Arizona
Originally Posted by vectorz
Do wheels weigh the same full of air, as they do without air?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
I packaged up some rims w/ the tires mounted, and forgot to let the air out..
Should I open it and start over?
Thread Starter
Melting Slicks
Joined: Oct 2003
Posts: 2,183
Likes: 5
Originally Posted by sailohio
There are no stupid questions. Just stupid people that ask them.
Sorry. I just had to do that.
Sorry. I just had to do that.
Thread Starter
Melting Slicks
Joined: Oct 2003
Posts: 2,183
Likes: 5
Originally Posted by sailohio
There are no stupid questions. Just stupid people that ask them.
Sorry. I just had to do that.
Sorry. I just had to do that.
So, all of you that posted snobby condescending answers need to take your head out of your @ss and start apologizing. Man I swear *some* of you old folks are snobby, even when you're wrong.
Racer
Joined: Aug 2001
Posts: 469
Likes: 0
From: Pasadena MD
Originally Posted by rickko
---> My answer: Depends if you replaced the Winter air with Spring, or Summer air.
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
---> A better answer:
When one asks a person: "What is air?", many times this answer is heard: "Nothing, or virtually nothing". Explain to the audience that air consists of small particles, molecules. Let the audience estimate how much the weight (mass) is of 1 m3 of air.
A glass bottle, that contains 1 liter of air, is placed on a balance. The weight is read from the display or scale.
The bottle is now evacuated and put on the balance again. The weight is read again.
Observe how the weight is diminished. The difference in weight, read from the scales, is about 1,3 g. When the air is admitted to the bottle again, the original weight reappears.
Explanation 1, 2 :
At the first measurement the total weight of the bottle and air together is determined.
Then, by means of a suction, the air is taken out of the bottle. When the bottle is weighed again, only the weight of the bottle itself is measured. The difference in weight is the weight of the air that was in the bottle. In this measurement the result is: the weight (mass) of 1 liter of air is about 1,3 g. As 1 m3 contains 1000 liter, the amount of air in a volume of 1 m3 is 1000 times as much as in 1 liter. So 1 m3 of air weighs about 1300 g, that is about 1,3 kg, which is rather substantial!
Got that? 1 cubic meter (~35.3 cubic feet) of air weighs 1300 grams or ~3 lbs.
---> Best answer:
You can use the Ideal Gas Law to determine the weight (mass) of the air in
your balloon. The law is
pV = nRT
The variables in this equation, with SI units are:
p - pressure (Pa)
V - volume (m^3)
n - moles (mol)
R - universal gas constant - 8.314 Joules / mole Kelvin
T - temperature (K)
If you solve for the number of moles, n, you can then use the following
relationship to calculate the mass:
m = nM
where
m - mass (g)
M - molecular weight (g / mol)
This mass is what a force must react against when accelerating the object
and is sometimes described as the inertial mass (per Newton's Second Law).
Now, if your ballon is filled with room temperature air (not hot), it may
not "feel" like it weighs the amount calculated by the above equations.
This is because it is surrounded by air and has neutral buoyancy. Also,
as you move it through the air, you will feel more resistance than would
be expected by its mass. This is because of the drag on the balloon by
the surrounding air.
Once you heat the air in the ballon, it will have buoyancy becuase it will
be less dense than the surrounding air. If you repeat the calculation
above, using the higher temperature, you will find there is less mass of
air in the same volume of balloon. Density is just the ratio of mass to
volume.
In the atmosphere, density decreases with altitude, so you hot air balloon
will rise until its average density equals the average density of the
surrounding air, thus achieving neutral buoyancy.
These concepts are explained in greater detail in any college level
physics textbook.
By, Christopher M. Seaman
Alcoa Technical Center
None of these examples consider compressing the air but I imagine for each cubic meter of air you can compress into a container, its overall weight will increase by ~3 lbs. Now you've got to figure out how much air creates a psi (Pressure).
What do you think?
..rickko..
Your hypothesis is incorrect. Air is not an ideal gas!
