Quote:
Originally Posted by
kwatson 
Shame about the state of physics education on this forum. There'll be absolutely no difference between 13,500 feet and somewhere around 100-300 feet for a flat plate shaped object. Terminal velocity for the phone is much less than for a human, perhaps only 50 ft/sec or so.
^^this
from 13,500ft, after the initial acceleration surely the ipod will actually start slowing as it passes through the thicker soupy air of the lower atmosphere
a cube has drag coefficient of about 1.05, a rectangular slab like an iphone will have higher drag
using
http://www.calctool.org/CALC/eng/aerospace/terminal and iphone 4 weight and dimensions on apple's product page
mass 0.137 kg
falling end on (highly unlikely it'd do this), cross sectional area 0.00054m^2
gives terminal velocity a smidge under 56m/s at sea level
but it's not going to fall end-on
falling flat side down it'd have area more like 0.0068, giving just 16m/s
a brick has drag of 2.1, so split the difference and say Cd of 1.5 for an iphone (i'd guess that's too low), make the wild assumption that terminal velocity will be the average of end on and face on, and you get about 30m/s, or 98feet/s for the imperially denominated
which it'd reach in a few seconds, or a few hundred feet
i.e. the first 13,000 feet were just needless attention seeking
caution: as will be apparent, i am not an aerodynamicist