wrote in message
...
Is a pressurized air object heavier?
In other words, is an object heavier when it contains compressed air
than when it's empty? For example, if I have a tire and weigh it
before pumping it full of air, will it be heavier after it's pumped
up? I say NO. A friend of mine insists it will be heavier once it's
filled with air. Who is right?

This is one of those fun topics that no one can agree on, and would
require a very accurrate scale that would most likely need to measure
down to the milligram.

Are you an idiot? They fill propane tanks by weight. What do you think?

This is one of those fun topics that no one can agree on, and would
require a very accurrate scale that would most likely need to measure
down to the milligram.

Are you an idiot? They fill propane tanks by weight. What do you think?


He's talking about compressed AIR...not LIQUID propane... ROFL...

"Jim & Lil" wrote in message
...



This is one of those fun topics that no one can agree on, and would
require a very accurrate scale that would most likely need to measure
down to the milligram.

Are you an idiot? They fill propane tanks by weight. What do you think?


He's talking about compressed AIR...not LIQUID propane... ROFL...
Yes, I realized that as soon as I hit send; though liquid propane is
compressed gas propane. and liquid air is compressed air: so it is the same
thing only completely different.

A more appropriate example would be comparing the weigh of a full scuba tank
and and empty. Don't need a very sensitive scale for that.

"Jim & Lil" wrote in message ...



This is one of those fun topics that no one can agree on, and would
require a very accurrate scale that would most likely need to measure
down to the milligram.

Are you an idiot? They fill propane tanks by weight. What do you think?


He's talking about compressed AIR...not LIQUID propane... ROFL...

I'll just laughing at you. It's all the same thing. The more you put in, the more it weighs.

Bob

Propane is liquid. (LP = Liquid Propane) (Now who is the idiot?)
Liquid is a big difference from air.

Actually, it's not. A liquid is only a liquid because of temperature
and pressure combination. IOW, you can take any gas, compress it
enough, and it will become liquid.


However, that website that John
posted does prove I am wrong. I just wonder how much weight is added
to a 15" tire when 32 lbs of air is added.

You can figure it out if you know the volume of the tire.

"Larry Bud" wrote in message
oups.com...

Propane is liquid. (LP = Liquid Propane) (Now who is
the idiot?)
Liquid is a big difference from air.

Actually, it's not. A liquid is only a liquid because of
temperature
and pressure combination. IOW, you can take any gas,
compress it
enough, and it will become liquid.


However, that website that John
posted does prove I am wrong. I just wonder how much
weight is added
to a 15" tire when 32 lbs of air is added.

You can figure it out if you know the volume of the tire.

Do you mean the 32 pounds of air doesn't weigh 32 pounds?
:-)
Bob

In article .com,
says...

Propane is liquid. (LP = Liquid Propane) (Now who is the idiot?)
Liquid is a big difference from air.

Actually, it's not. A liquid is only a liquid because of temperature
and pressure combination. IOW, you can take any gas, compress it
enough, and it will become liquid.

Not *any* gas. There is no liquid phase of helium at room
temperature at any pressure.


However, that website that John
posted does prove I am wrong. I just wonder how much weight is added
to a 15" tire when 32 lbs of air is added.

You can figure it out if you know the volume of the tire.

Sure, 32psi is about 2ATM, so it will weight twice that of air at
0ATM (note: differential pressures). Air is mostly N2 and O2, so
it has a weight of, say 30g/mole (O2 is 32g/mole, N2 is 28g/mole).
At STP there are 22.4moles/l so that's about 375g/l. So, at 2ATM a
tire will weight about 750grams per liter of tire volume more than
it will deflated. That doesn't sound like it's going to to take a
tremendously accurate scale to measure. ;-)

--
Keith

In article , bobnospam1
@softhome.net says...

"Larry Bud" wrote in message
oups.com...

Propane is liquid. (LP = Liquid Propane) (Now who is
the idiot?)
Liquid is a big difference from air.

Actually, it's not. A liquid is only a liquid because of
temperature
and pressure combination. IOW, you can take any gas,
compress it
enough, and it will become liquid.


However, that website that John
posted does prove I am wrong. I just wonder how much
weight is added
to a 15" tire when 32 lbs of air is added.

You can figure it out if you know the volume of the tire.

Do you mean the 32 pounds of air doesn't weigh 32 pounds?
:-)

....or does it cost £32. ;-)

--
Keith

krw wrote:

Sure, 32psi is about 2ATM, so it will weight twice that of air at
0ATM (note: differential pressures). Air is mostly N2 and O2, so
it has a weight of, say 30g/mole (O2 is 32g/mole, N2 is 28g/mole).
At STP there are 22.4moles/l so that's about 375g/l. So, at 2ATM a
tire will weight about 750grams per liter of tire volume more than
it will deflated. That doesn't sound like it's going to to take a
tremendously accurate scale to measure. ;-)


Actually it is 22.4L/mole at STP; atmospheric pressure would be quite
great your way So 1 L of air at 2 atm would weigh about 2.7g.

In article . com,
says...
krw wrote:

Sure, 32psi is about 2ATM, so it will weight twice that of air at
0ATM (note: differential pressures). Air is mostly N2 and O2, so
it has a weight of, say 30g/mole (O2 is 32g/mole, N2 is 28g/mole).
At STP there are 22.4moles/l so that's about 375g/l. So, at 2ATM a
tire will weight about 750grams per liter of tire volume more than
it will deflated. That doesn't sound like it's going to to take a
tremendously accurate scale to measure. ;-)


Actually it is 22.4L/mole at STP; atmospheric pressure would be quite
great your way So 1 L of air at 2 atm would weigh about 2.7g.

Damn, sitting thinking about it after, I *knew* I screwed something
up. My calculation would have made a 1cu.ft. bucket of 2ATM air
weigh upwards of 50 lbs! Oops. Thanks for the catch! blush

--
Keith

In article , krw wrote:

Sure, 32psi is about 2ATM, so it will weight twice that of air at
0ATM (note: differential pressures). Air is mostly N2 and O2, so
it has a weight of, say 30g/mole (O2 is 32g/mole, N2 is 28g/mole).
At STP there are 22.4moles/l so that's about 375g/l.

Try again. Density of air at STP is 1.29 grams per liter.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On 28 Oct 2005 06:13:14 -0700, "Larry Bud"
wrote:


Propane is liquid. (LP = Liquid Propane) (Now who is the idiot?)
Liquid is a big difference from air.

Actually, it's not. A liquid is only a liquid because of temperature
and pressure combination. IOW, you can take any gas, compress it
enough, and it will become liquid.

Of course there is a diffference between liquids and gases. Liquids
run into the streams and gases float. AFAIC gases don't weigh
anything. When they talk about air pressure, they're referring to the
emotional tension of never knowing where one's next breath will come
from.


However, that website that John
posted does prove I am wrong. I just wonder how much weight is added
to a 15" tire when 32 lbs of air is added.

You can figure it out if you know the volume of the tire.

mm writes:

AFAIC gases don't weigh
anything.

Of course they weigh something.

Some are denser than air and sink.
For example CO2. Remember that village smothered in
Africa. That was CO2 rising from a lake then moving along
the ground.

Some are lighter than air and rise.
Helium is an everyday example.

Some like Nitrogen and Oxygen are about the same
as the mixture of gases we call air and just disperse.
If you weighed them on an everyday scale the scale would
say zero, but they have mass and are attracted to the Earth
by gravity.

Dan Espen wrote:
mm writes:


AFAIC gases don't weigh
anything.


Of course they weigh something.

Some are denser than air and sink.
For example CO2. Remember that village smothered in
Africa. That was CO2 rising from a lake then moving along
the ground.

Some are lighter than air and rise.
Helium is an everyday example.

Some like Nitrogen and Oxygen are about the same
as the mixture of gases we call air and just disperse.
If you weighed them on an everyday scale the scale would
say zero, but they have mass and are attracted to the Earth
by gravity.

Next question:

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Jeff Wisnia wrote:
Dan Espen wrote:
mm writes:


AFAIC gases don't weigh
anything.


Of course they weigh something.

Some are denser than air and sink.
For example CO2. Remember that village smothered in
Africa. That was CO2 rising from a lake then moving along
the ground.

Some are lighter than air and rise.
Helium is an everyday example.

Some like Nitrogen and Oxygen are about the same
as the mixture of gases we call air and just disperse.
If you weighed them on an everyday scale the scale would
say zero, but they have mass and are attracted to the Earth
by gravity.

Next question:

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.



Even better question, did mm just wake up from a year long nap? LOL

Canary question is interesting. My answer is the box would weigh the
same, because gravity is still acting on both the box and the canaries.
The upward force against the canaries wings which is keeping the
canaries in the air causes an equal an opposite force against the air,
which ultimately is transfered through the air and to the bottom of the
box, resulting in the force which we call weight.

wrote:

Jeff Wisnia wrote:


snipped

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.




Even better question, did mm just wake up from a year long nap? LOL

Canary question is interesting. My answer is the box would weigh the
same, because gravity is still acting on both the box and the canaries.
The upward force against the canaries wings which is keeping the
canaries in the air causes an equal an opposite force against the air,
which ultimately is transfered through the air and to the bottom of the
box, resulting in the force which we call weight.


Your correct of course, but the simpler answer is just that the mass of
the box and all the stuff inside it stays the same, so its "weight" must
too.

Fot thse who don't already know this one, which way does a kid's free
floating helium balloon moored on a string inside a schoolbus move when
the bus decelerates, and why?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

Jeff Wisnia wrote:
wrote:

Jeff Wisnia wrote:


snipped


Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.





Even better question, did mm just wake up from a year long nap? LOL

Canary question is interesting. My answer is the box would weigh the
same, because gravity is still acting on both the box and the canaries.
The upward force against the canaries wings which is keeping the
canaries in the air causes an equal an opposite force against the air,
which ultimately is transfered through the air and to the bottom of the
box, resulting in the force which we call weight.


Your correct of course, but the simpler answer is just that the mass of
the box and all the stuff inside it stays the same, so its "weight" must
too.

Fot thse who don't already know this one, which way does a kid's free
floating helium balloon moored on a string inside a schoolbus move when
the bus decelerates, and why?

Jeff


Relative to the bus, or to the ground

nate

--
replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

On 2 Dec 2006 08:51:44 -0800, wrote:



Even better question, did mm just wake up from a year long nap? LOL

You noticed that! Very good.

Jeff Wisnia wrote:
have mass and are attracted to the Earth
by gravity.

Next question:

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the
inside bottom. G

Another question involving "sublimation."

There is only one common substance that transforms directly from a solid to
a gas without passing through a liquid phase first. What is it?

(answer below)












A taco.

In article ,
says...
wrote:

Jeff Wisnia wrote:


snipped

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.




Even better question, did mm just wake up from a year long nap? LOL

Canary question is interesting. My answer is the box would weigh the
same, because gravity is still acting on both the box and the canaries.
The upward force against the canaries wings which is keeping the
canaries in the air causes an equal an opposite force against the air,
which ultimately is transfered through the air and to the bottom of the
box, resulting in the force which we call weight.


Your correct of course, but the simpler answer is just that the mass of
the box and all the stuff inside it stays the same, so its "weight" must
too.

Fot thse who don't already know this one, which way does a kid's free
floating helium balloon moored on a string inside a schoolbus move when
the bus decelerates, and why?

The direction of acceleration. Because it's lighter than the air
around it.

--
Keith

In article ,
says...
Jeff Wisnia wrote:
have mass and are attracted to the Earth
by gravity.

Next question:

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the
inside bottom. G

Another question involving "sublimation."

There is only one common substance that transforms directly from a solid to
a gas without passing through a liquid phase first. What is it?

There are lots, but snow comes to mind. Dry ice?

(answer below)












A taco.

Ever barfed one up?

--
Keith

In article , Jeff Wisnia wrote:

Will a closed box with a bunch of canaries in it weigh less if the
canaries are flying around than if they are walking around on the inside
bottom. G

If the box has been closed long enough, the canaries will all be lying on the
bottom of the box, dead of suffocation.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.