MadSci Network: Earth Sciences |
Paul, regarding your question on the pressure inside and outside any airplane. The answer is that the pressure is relative to standard pressure, that is what the pressure is at ground level, 14 pounds per square inch. Since air pressure gets smaller the higher you go up, and an absolute vacuum would be 0 pounds per square inch (psi), the highest pressure difference between the outside and inside of a plane is 14 psi. This pressure is easily overcone by the structural integrity of the plane. And this is also the reason why the pilots cannot be crushed by the pressure inside the plane. The cabin pressure is attempting to maintain ground pressure or about 14 psi. Since pressure on the ground is 14 psi, and that pressure is what is maintained by the cabin, the pilots would feel just the same as they would on the ground, no matter how high they flew. However, if you take a plane down to the ocean bottom where outside pressures are much greater, (pressure increases by 14 pounds every 33 feet) the cabin would crush and the pilots as well because the pressure difference is much much greater. Pressure 1 mile down would be well over one ton per square inch!!!!! Submarines are built to withstand these pressure, but even they have depth limits. Hope this helps. -- Carlin Gregory, Williams Gas Pipelines-Texas Gas
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