by dukey » Wed 06 Dec 2006, 11:50:44
I was curious for my own benefit ..
just how much of a difference air resistance would make
what speed do sky divers reach before they hit terminal velocity ?
$this->bbcode_second_pass_quote('', 'F')or example, the terminal velocity of a skydiver in a normal free-fall position with a closed parachute is about 195 km/h (120 mph or 54 m/s).
Source:
http://en.wikipedia.org/wiki/Terminal_velocityObvisouly a sky diver is not a falling building, but it gives us some idea.
Both me and lighthouse calculated the final speed (in a vacuum) that the top of the building would reach just before it hit the ground at around 90 m/s. (The building would take aproximately 9.2 seconds to completely collapse.)
Factoring in, some very rough approximation of the sort of difference air resistance might make. I am sure now, more than ever,
those buildings simply fell out the sky (demolition style) ;p
One more quote, again straight out of wikipedia
$this->bbcode_second_pass_quote('', 'I')n 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.