Bullet Impacts Crayons
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- Опубліковано 30 лис 2022
- How much energy is transferred from a bullet to a crayon during an impact? Does it pass with insignificant energy/speed loss? How many crayons should it take to completely stop a bullet? Very difficult to guess without some testing... A fun way to go about this is to fire a bullet through a series of crayons and determine the speed delta from before and after impact. Then, you could approximate the energy transfer during an impact by subtracting the bullet initial kinetic energy from its final kinetic energy (i.e., when the bullet is roughly through the crayon array). By definition, the KE = mv*v/2. The delta in energy came out to be 169 J, nearly a 40% loss in energy from 425 J! Based on this data, it would be interesting to see what people guess would be the total number of crayons needed to stop the bullet.
Please note that this test was conducted on a controlled ballistics range with all the necessary precautions to ensure the safety everybody who was involved. I do not encourage that anybody repeat this test in any other context.
This video was captured with the Phantom TMX at 76000 fps, 3 us exp, and 100 mm Zeiss makro. Enjoy.
very interesting to see the energy transfer calculated
Straight to the point…thank you
Interesting to see how the first crayon is less pull up as the last
my guess is that there is debris from the earlier crayons that contribute to the rotation of the last crayons... what also supports that is the fact that the rotation angle increases from left to right... since each crayon from left to right has more and more off-axis debris !
@@kdgilroy4it is a great explanation with an impacting film
This is the greatest channel I've found in a while. Phenomenal content, great to watch as food for thought.
love these videos
(bullet / crayons) * 47 seconds = stupidly entertaining!!!
😂😳🤓
I think it’s more fun to just keep shooting the crayons to find out how many it takes 🤓
crazy how a bullet lost almost half its energy from hitting a crayon
Hi Kyle! Curious if you’re considering the rotational energy in the kinetic energy calculations? (Not sure how accurately you can calculate this, particularly after the impact…)
awesome question, when the bullet embeds into the crayons, I get the speed of the bullet by tracking its tail (the rest of bullet is hidden). Its difficult to see the change in rotation... but it is very likely that the rotation could have slowed and gave its rotational kinetic energy to the crayons that manifested itself in an energy transfer. The way to do that properly would be to use high speed xray... which sounds like a fun follow up test :)
@@kdgilroy4 Yes, I was looking for the rotation before and after, and definitely couldn’t see enough of the bullet after. Perhaps if you were able to shoot a wider frame so you can estimate rotation once some of the debris clears? Unless you’re just wanting to use more sophisticated methods and show off your cool toys… 😉 I would think the rotational energy would be important to consider, particularly seeing how much rotational energy bullets have from watching videos of bullets spinning like tops after shooting them into ice.
Just curious if you remember me? 😉
Beautiful! What do you use for lighting? Very curious.
Hey, thanks! A pair of GS Vitec QT lights and an IES 4438 to light the background.
Also... love what you guys do, keep it up!
@@kdgilroy4 thanks so much! If you know of any phantom cameras for sale, or know how I can get access to some of the higher end phantoms, please let me know! I would love to buy one
@@BallisticHighSpeed for that, you can write into phantom-support@ametek.com and they would direct down the right channel!