How many pounds of air will it take to  make the average man bouyant?
443013
It depends on how far out of the water you wish to be.  Humans are very close to being bouyant-we are more dense than water, but have lungs full of air, thus a lean man with a large lung capacity is bouyant with a deep breath.  Its isnt the pounds of air that matter, its the pounds of water displaced by the air.  If you hold onto a 10 gallon jug full of air, it displaces 10 gallons worth of water, which is about 80 pds-well more than you need to keep your upper body above water.  For a 200 pd man, he would need an water-displacing container of 25 gallons (this could be a boat or anything else that displaces water for air).
42801
Aprox 5lbs per minute give or take 5lbs
235622
Depends on a persons metabolism
1048021
Between 52-66kg (114-145lbs - I think) based on the Body Mass Index.  Hope this helps.
1144696
gravity and air resistance.
1063108
From one inch to 3/4  depending on length less than 500 feet and the demand for air at the station\n\n...\nno
165042
Air has its own weight. It's quite easy to demonstrate this by weighing an empty balloon on a set of accurate scales. Then pump the balloon up with a bicycle pump and weigh it again. The balloons got heavier. The reason it's got heavier is because the balloon is now full of compressed air. If air didn't have any weight, then the balloon with compressed air in it would weigh the same as the empty balloon. Because its heavier, we've demonstrated that air has weight. \n\nBecause the weight of air varies with pressure and temperature it has to be defined accurately. Meteorological offices and aviation textbooks use the following figures. \n\nThe weight of dry air (no moisture content) at 0 deg C and under a normal atmospheric pressure of 1013 mbar is 1.293 Kg/cu metre. \nThe weight of dry air (no moisture content) at 0 deg C and at a pressure of 1000 mbar (1 Bara) is 1.275 Kg/cu metre. \n\nSo find out the volume of the room ie lenght x breadht x height and apply the above values.
434818
breath. air is the wrong answer because it doesn't make sense that a man can hold air for long.
403111
well yea he is right to a point. it falls on the person that is using the tank. the bigger and/or taller the person is the more air they would use and the smaller the less. easy way to explain it is. think of a small car vs a huge truck. which uses more gas ??
596583
Mass. I think.Depending on how strong the gravity is your mass changes.
806738
If you use a heavy enough weight then the effects of air are minimal.
915015
You would need a tank about the size of a house (55ft cube) unless you compress the air then it would be much smaller.
342770
"Good" lung capacity is a general term used to describe an individual's breathing in relation to many factors specific to that person, such as weight, sex, age, and activity. \nThe average total lung capacity is approximately 5.8 liters (5800 cm3), however it varies from person to person, and is dependent on the factors discussed above. \n\nWomen tend to have 20 - 25% lower total lung capacity than males. Tall people tend to have a greater total lung capacity than shorter people. Heavy smokers generally have a drastically lower total lung capacity than non-smokers. \nTo find out if your lung capacity is "good" or "bad", you should talk to your doctor - preferably a pulmonologist.
783986
1-2 lbs, depends on your resting metabolism.
517724
About 110 Lbs or seven stone twelve for you Brits.
1006329
Normally between 5-7 liters, depending on the size of the person, or 7-8% of the persons body weight
311098
Not very much.  The water pressure on your body would prevent you from being able to bring in air that is at normal atmospheric pressure.  You need a compressor on the surface and a hose to breath from.