Are the changes in atmospheric pressure-ratio constant with height?
93783
I think one has to recalibrate your barometer for every different location (including altitude), according to what I read on the internet and my intuition. \n\nI am working on a more quantitative analysis which I will try to complete to post here later.
165378
Standard sea level barometric pressure is 1013 Millibars. When the needle goes above this, it indicates a High pressure. When the needle drops below, it indicates Low pressure.\nGo to a weather page like http://www.wunderground.com/global/CI_Index.html\nIt will tell you the pressure.
1144696
gravity and air resistance.
725587
Air gets less dense at higher altitudes, so fewer BTU's are required to heat the same volume of air, and is proportional to the altitude.\n\nAir density varies logarithmically with altitude, so you need to correct the standard BTU heating formula by a logarithm related to altitude.  I'm at 5050 ft altitude, and the air density is 20% less than at sea level.  The correction factor for furnace sizing is therefore 1.20, which can be confirm on page 15 of the first link below.\n\nIf you want the theory behind the calculations, check out the second link - it shows the logarithmic relationships of pressure vs. altitude.
1146161
The barometric formula, sometimes called the exponential atmosphere, is a formula used to model how the pressure (or density) of the air changes with altitude. It is based on the simplifying (not very realistic) assumption that the temperature does not depend on altitude. However, this formula agrees reasonably well with the actual pressure and density variations above the earth's surface up to a height of about 450,000 ft (140 km).\n\n \np=p0exp(-Mg0z/RT)\n\n\n\n \nwhere h is the scale height, ρ (rho) is density, P is pressure, P0 is pressure at ground level (mean sea level pressure is 1013.25 hPa), M = 0.029 kg mol-1 (the mass of 1 mole of air), R = 8.314 J K-1 mol-1 is the gas constant, T is temperature, g0 is the acceleration due to gravity (about 9.8 m s-2 depending on your location) and z is the vertical height above the earth's surface.\n\nUsing the same principles, the above equation can be solved for altitude as a function of pressure. This formulation is known as the hypsometric equation.\n\nAs a rule of thumb, the pressure decreases by about 1% for every 80 metres increase in altitude.
423881
true - high sustained pressure and a signifigant distance to any pressure disturbance or variation
897109
atmospheric pressure decreases as altitude increases.\n(think about gravity)\n\nan object that floats is less dense than the fluid it floats in.\n"A piece of the object weighs less than a piece of the fluid the same size."
387707
Temperature decreases w/ height as you move up through the troposphere b/c of a decrease in air pressure.\n\nAir pressure steadily declines as you move up b/c there is less gravity. Since gravity acts on everything that has mass, including air, it holds most of the earth's air close to the ground. Air acts as an insulator or blanket, absorbing long wave radiation reradiated from the earth. When you move upward away from the surface, the air thins out. There is less air to hold heat.\n\nHowever, once you leave the troposphere, you enter the stratosphere. Here the temps steadily increase due to the presence of the ozone layer. The ozone traps heat.\n\nAs you move away from the stratosphere you will enter the mesosphere where temps decrease again due to less air & movement away from the ozone layer.\n\nAs you go even higher & enter the Thermosphere, the temps increase again b/c solar radiation is so intense that the few air particles that are present are super heated. The chances of being burned are slight to none b/c the air particles are few & far between. After all that is what is holding the actual heat.
581432
atmospheric pressure, winds, light
1129634
As you go up in altitude, the air does get cooler since it's less dense, and can therefore retain less heat.  However, this heat loss is 2 degrees Celcius per 1000 feet.  So, for the height of a three story house, at about 35 feet, the cooling effect would be .07 of a degree.  Hardly enough to notice.  You have to go much higher than your house to notice any cooling effect.  The air near the surface is constantly in motion, and you can't measure differences over such a short scale.\n\nAnyway, as others have stated, hot air rises, and unless you have a large vent on your top floor, it will collect there and heat the upper floors.
775141
Proportionate. Increase in temperature results in increased pressure.
874775
ignor the atmospheric changes, it would be 4.8s if I'm not mistaken
317634
Pressure will increase if temperature increases, assuming that the container remains at a constant volume. Because the molecules are moving faster, they collide more often with the walls of the container, so the pressure goes up.\n\nThis is demonstrated by Gay-Lussac's Law, which states that that for a fixed amount of gas (fixed number of moles) at a fixed volume, the pressure is proportional to the temperature, so:  P/T = constant.\n\nIn case you need to know this for a test, and easy mnemonic  is "Pete and Tom are Gay" (Pressure and Temperature are proportional according to Gay-Lussac).
554161
As answer 4 implies, it defies simple description and modeling, since the lapse rate (rate of change of temperature with altitude) depends on air humidity, and of course that can vary. Up to about 11 KM altitude you can approximate the lapse rate as 6.5 C per km (ref. 1), but that applies to an "international standard atmosphere" which may not exist in your application.\nLooking at the diagrams at the bottom of the page in ref. 2, you can see how a typical real-world weather situation (warm water-laden air blowing onto the shore and passing over a mountain) has a more complex temperature profile.
218879
It seeks its equilibrium, meaning that it rises to the altitude at which the air within and without are at equal pressure.  Volume does not change.
1031939
temperature decreases with increase in altitude
58327
Pressure goes up as temperature goes up.