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projectile velocity guesses

Posted: Tue Mar 17, 2009 6:50 pm
by rp181
Hey all. I fired the railgun again, it was the best shot yet. Can anyone guess the velocity of it? It put a hole in .02" steel plate. The projectile is .5"x.5"x1" aluminum.

Very last shot on:

Posted: Wed Mar 18, 2009 3:46 pm
by psycix
Awesome sparks!
Too bad there was music over the sound of it...
I have absolutely no idea of the muzzle velocity of this thing. What is it?

Posted: Wed Mar 18, 2009 4:31 pm
by Biopyro
You can make a rough estimate by measuring the distance the projectile is traveling fo and then finding out how many video frames it appears in. If you know the framerate you can do it fairly well

10m, appears in 2 frames at 30fps so it took 2/30 s to travel 10m 10/0.666=150 so it was around 150m/s.

You could also use a microphone to measure the time between the firing sound and the sound of it hitting the target.

http://www.spudfiles.com/forums/viewtop ... 0%90%89%AC

Posted: Thu Mar 19, 2009 2:07 pm
by jimmy101
Biopyro wrote:You could also use a microphone to measure the time between the firing sound and the sound of it hitting the target.
Or, just extract the audio track from the video, assuming the video has an audio track.

Posted: Thu Mar 19, 2009 2:57 pm
by rp181
I tried that. The quality sucks too much. On the plus side, I may be getting access to a phantom 5.1 high speed camera.