Prove that air has mass

iliopsoas

Golden Member
Jul 14, 2001
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What's a simple experiment to prove that air has mass? It only has to be qualitative, not quantitative.

A friend asked me this and I couldn't come up with anything :( It's been too long since the old physics days.
 

TheoPetro

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Nov 30, 2004
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are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.
 

iliopsoas

Golden Member
Jul 14, 2001
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Originally posted by: TheoPetro
are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.

Ahhh. I thought of that. But how do you ensure that both balloons weigh the same? And wouldn't this just test density and not necessarily mass?
 

Rubycon

Madame President
Aug 10, 2005
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You could take a field trip to Washington D.C. if your experiment involves copious amounts of hot air. :laugh:
 

iliopsoas

Golden Member
Jul 14, 2001
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Originally posted by: TheoPetro
would you like an exact expairment? or do you want something you can do at home?



no, not an exact experiment. Just something quick and simple.
 

TheoPetro

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Nov 30, 2004
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Originally posted by: MS Dawn
You could take a field trip to Washington D.C. if your experiment involves copious amounts of hot air. :laugh:

why go that far when P&N is just one floor down?
 

TheoPetro

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Nov 30, 2004
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Originally posted by: iliopsoas
Originally posted by: TheoPetro
would you like an exact expairment? or do you want something you can do at home?



no, not an exact experiment. Just something quick and simple.

then the baloon thing is quick and simple. you can get a scale to measure them first.
 

fire400

Diamond Member
Nov 21, 2005
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Originally posted by: TheoPetro
are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.

ROFL u got this one b4 I did
 

AbAbber2k

Diamond Member
Mar 1, 2005
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Originally posted by: iliopsoas
Originally posted by: TheoPetro
are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.

Ahhh. I thought of that. But how do you ensure that both balloons weigh the same? And wouldn't this just test volume and not necessarily mass?

:disgust:

Good god...
I've never seen anyone more oblivious to the completely obvious.
 

Soccer55

Golden Member
Jul 9, 2000
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How about if you find the mass of a container. Then suck the air out of the container and find its mass. You might be able to do this by putting the container in a vacuum or something like that. The difference between the two masses is the mass of air.

-Tom

EDIT: Just for clarification, by "put the container in a vacuum" I don't mean the electronic device that gets crap out of rugs. I mean the scientific definition of vacuum. :p
 

TheoPetro

Banned
Nov 30, 2004
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IVE GOT IT!!!!!! weigh your head....then suck the air out of it...then weigh it agian

Edit: drat soccer55 beat me to the idea
 

h8red

Senior member
Jul 24, 2001
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Weigh a canister of compressed air. Remove air from canister. Weigh empty canister. Or do it with a balloon as said before
 

giantpinkbunnyhead

Diamond Member
Dec 7, 2005
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Air has mass because:

1) Sound can travel through it. Sound cannot travel through a void.

2) Air is composed of nitrogen, oxygen, water vapor, and trace gases. All of these have molecular weights, and therefore... they have molar mass.

3) Sea level pressure is usually 14.7 psi per square inch. That means that a column of air one inch square, stretching from the ground to the top of the atmosphere, weighs 14.7 pounds by definition.

4) A helium balloon floats not because helium has negative weight but because it weighs less than the air around it. This in itself should prove that air does indeed have mass.


 

91TTZ

Lifer
Jan 31, 2005
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Originally posted by: TheoPetro
are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.

That is not a good test at all.

Helium has mass, but if you did your test and compared the helium-filled balloon to the deflated balloon, the helium balloon would be lighter. The test would erroneously "prove" that the "nothing" in the deflated balloon has more mass than the balloon filled with helium.

Your test tests bouyancy, not mass.
 

I Saw OJ

Diamond Member
Dec 13, 2004
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Originally posted by: 91TTZ
Originally posted by: TheoPetro
are you kidding?

well heres your homework help from me. take 2 baloons. Blow one up. set the deflated one on one side of a balance and set the inflated one on the other side.

That is not a good test at all.

Helium has mass, but if you did your test and compared the helium-filled balloon to the deflated balloon, the helium balloon would be lighter. The test would erroneously "prove" that the "nothing" in the deflated balloon has more mass than the balloon filled with helium.

Your test tests bouyancy, not mass.

When did he say anyhting about helium? blow the ballon up with your lungs.