User:Geek.not.nerd
As altitude increases, atmospheric pressure decreases. One can calculate the atmospheric pressure at a given altitude. Temperature and humidity also affect the atmospheric pressure, and it is necessary to know these to compute an accurate figure. The graph at right was developed for a temperature of 15oC and a relative humidity of 0%.
The equation relating atmospheric pressure to altitude and other parameters is
(insert equation)
Where the height, h, is in meters and the constant parameters are as described below:
| Parameter | Description | Value | ||
|---|---|---|---|---|
| P0 | sea level standard atmospheric pressure | 101325 Pa | ||
| L | temperature lapse rate | 0.0065 K/m | ||
| T0 | sea level standard temperature | 288.15o | ||
| g | Earth-surface gravitational acceleration | 9.80665 m/s2 | ||
| M | molar mass of dry air | 0.0289644 kg/mol | ||
| R | universal gas constant | 8.31447 J/(mol•K) | ||
External Links
Air Pressure vs. Altitude YouTube video from the Naval Aviation Museum accessed 05032011
Air Pressure at Altitude calculator at altitude.org This site also contains information about altitude sickness and the effects of altitude on oxygen in the blood.
References
- ^ A Quick Derivation relating altitude to air pressure by Portland State Aerospace Society, 2004, accessed 05032011