on mon sep NUMBER NUMBER at NUMBER NUMBER NUMBERam NUMBER john hall wrote why so fast normal terminal velocity is much slower terminal velocity can be calculated by v_ t sqrt frac NUMBERmg cpa where c is an experimentally determined coefficient p is the density of the air and a is the area of the object these calculations only work if the object is blunt and the airflow is turbulent blah blah blah terminal velocity for a skydiver actually varies with how the diver holds themselves you go faster if you pull yourself into a cannonball that is the a for the most part all else being equal the terminal velocity is inversely proportional to the square root of air density air density drops off pretty quickly and i really should be doing something other than digging up the math for that i think it involves calculus to integrate the amount of mass as the column of the atmosphere trails off i grabbed the other stuff directly out of a book in NUMBER a guy named gregory robertson noticed a fellow parachutist debbie williams had been knocked unconscious he shifted so that he was head down hit about NUMBER mi h and caught up with her and pulled her chute with NUMBER seconds to spare njl 