Nike Ballistic Lawn Dart

5 responses to “Nike Ballistic Lawn Dart”

1. 

   louv

   Oct 6, 2007 at 5:44 pm

   so sad.
   (how fast were you shooting these? that is to ask: what was its terminal velocity?)

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2. 

   jurvetson

   Oct 6, 2007 at 5:53 pm

   For a a sense of scale…

   Louv — Motor drive, which on the Canon 5D is about 1/3 sec apart. There are two frames between these two, but those are also post-impact.

   In other words, the rocket hits the ground in less than .3 seconds after the frame on the left here.

   What do you estimate?

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3. 

   louv

   Oct 6, 2007 at 6:23 pm

   My guess is somewhere between 150 and 250 mph.
   Assumptions:
   1) 19ft rocket, approx 4 "rocket lengths above the ground" in first pic.
   2) If the next image was post impact then it traveled 76 feet in something between .2 (a guess) and .333 seconds (the next frame).
   3) then convert ft/sec to mph, and the results are 250 & 155 mph.

   Of course, since the next frame is post-impact, it is nearly impossible to tell when it actually hit, therefore with out two frames of "flight" and a way to measure the distance, we’re just guessing.

   But it is safe to say "at least 150 mph at impact".

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4. 

   [Magec]

   Oct 15, 2007 at 9:04 pm

   wow! boom!

   Reply
5. 

   jurvetson

   Feb 10, 2008 at 11:24 pm

   and these photos made it into Rockets Magazine =)

   

   Reply