From Wikipedia, Terminal velocity.
I Don't know if this helps you at all.
Based on wind resistance, for example, the terminal velocity of a skydiver in a free-fall position with a semi-closed parachute is about 195 km/h (120 mph or 55 m/s). This velocity is the asymptotic limiting value of the acceleration process, since the effective forces on the body more and more closely balance each other as the terminal velocity is approached. In this example, a speed of 50% of terminal velocity is reached after only about 3 seconds, while it takes 8 seconds to reach 90%, 15 seconds to reach 99% and so on. Higher speeds can be attained if the skydiver pulls in his limbs (see also freeflying). In this case, the terminal velocity increases to about 320 km/h (200 mph or 90 m/s), which is also the terminal velocity of the peregrine falcon diving down on its prey.
Your theory is crazy, but it's not crazy enough to be true. - Niels Bohr
Ad eundum quo nemo ante iit
Hint: this is at heart a scientific forum, and underneath the fooling around there are some diamond-hard minds hanging about, ready to tear you to shreads. -- Mike Alexander