#### Terminal velocity

@ CAD MONKEY

Terminal velocity for a human in a typical arms and feet out pose is ~ 120 mph. In a nose dive a human can exceed 200 mph. Last I checked a pea was a brave bit smaller than a human...

The terminal velocity for a pea sized rock is -

Vt=(0.2222*g*(dm-da)*(r^2)/n

where * stands for multiplication, / stands for division

g is the acceleration of gravity (~980 cm/s^2)

dm is the density of the meteorite (~2.7-3 g/cm^3 for rock)

da is the density of air (~ 0.0012923 g/cm^3)

r is the radius (half the diameter) of the metorite in cm

n is the dynamic viscosity of air near the Earth's surface (~ 0.00018 g/cm/s).

thus the terminal velocity for a 0.3 cm meteorite with a density similar to granite is ~ 1800 mph.

What speed it was actually doing is another matter, but it could have potentially been zipping along ;)