Justin Li

Airplane Physics

2007-09-19

I just realized that I'm in a tube suspended by nothing but air. I know that the plane is thrust forward by the engines, moving air over and under the wing, and by the airfoil design there is less air pressure on top, and so the wing and the aircraft is pushed upward by the larger air pressure. But it's still pretty amazing. I think it's over a 30 second drop... slightly more than 43 seconds, actually, assuming a cruising attitude of 30,000 ft and 32 ft/s2 gravity. Yay physics. So I'm in a metal tube doing maths and typing. Great.

x = x0 + v0 t + 1/2 a t\^2
0 = 30000 - 1/2 32 t\^2
t\^2 = 30000 / 16 = 1875
t\^2 = 1875 \~ 1849 = 43\^2
t \~ 43 s

No hijackers in sight.