Överleva flygplanshopp?

The best high jumper in the world jumps somewhere around eight feet. Now he actually only raises his center of gravity about four feet (I use round numbers to make things easy). His velocity when he loses contact with the ground is given by v\,=\,\sqrt{2gh}. (Note the convenient numbers I have chosen) his maximum vertical velocity is the square root of 2*32*4 which is exactly 16 ft/sec. That translates to 10.9 miles per hour.