For 10 points, name this quantity, the distance an object is from the surface of the earth.
Pressure is proportional to the exponential of this quantity in the hypsometric equation. Devices measuring this quantity often have three pointers and use an aneroid barometer. As this quantity increases, temperature decreases, then increases, then decreases again, since the lapse rate changes sign. The Karman line is defined as the limit of this quantity at which (*) lift velocity equals orbital velocity. Gravitational acceleration decreases with the square of this quantity. It increases from the mesosphere to the thermosphere to the exosphere. For 10 points, name this quantity, the distance an object is from the surface of the earth.
Pressure is proportional to the exponential of this quantity in the hypsometric equation.
altitude [or height; or elevation; prompt on distance or radius]