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This is the Devtac Ronin. The company claims...
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You are currently reading a thread in /k/ - Weapons

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This is the Devtac Ronin. The company claims that this mask is level IIIA, or, to oversimplify, capable of stopping a 357 SIG or 44 magnum round.

My question is, stopping the round or not, can you even survive that level of energy transfer to your head? Wouldn't it give you a closed head injury?

People more knowledgeable than me, please discuss
>>
I feel if someone can accurately shoot me in the face with a handgun I've already fucked up at least ten things I should've considered before a robo ninja mask
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>>28575683
you'd be concussed, but thats infinitely better than dead.
Was that really something you couldn't figure out without making a stupid thread on /k/?
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>>28575683
Let's face it, nobody is going to buy this for protection.
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>>28575701

This
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>>28575683
>Iet's just strap fucking rails on everything
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>>28575701
so you can only get hit in the head when someone shoots accurately?
Luck plays no part in this whatsoever?
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>>28575683
Who wants to bet someone is gonna buy one just to paint a Punisher Skull on it.
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>>28575704
>closed head injury
>concussed

1/10 you tried
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>>28575683
I think you would live, but the impact would turn you into a charlie carrot.

Or ya know, gunned down by the follow up shots somebody does on your disoriented now retarded cuncussed ass
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>>28575741
I reverse Google searched it, it already exists.
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>>28575754
just how fucking retarded are you, son?
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>>28575683
https://cryeprecision.com/ProductDetail/hlmac108000_airframe-chops

Infinitely more practical.
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>>28575775
We're talking hematomas, contusions, and axons, not pussy ass concussions

you know something a fucking 44 magnum would do and not some fat american landing on you funny
>>
Lets assume you get hit with the largest round that that mask can stop.

You already have a concussion, no doubt. The next question is if you're lucky, and the mask indented enough to break a cheekbone, or you're not lucky, and the force of your head jumping back will give you permanent neck injuries.

I'll take a broken face over a lifetime of neck pain, but the point is moot since both are preferable to being dead.
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>>28575683
>wanting to be AntMan
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>>28575809
a concussion would be infinitely more likely depending on handgun caliber, and distance of shot.
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>>28575683
I kinda want one, just for the hell of it. Where can I get one?
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>>28575881
"no"
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>>28575988
and if you wanna double down for 44 magnum
>>
A .44magnum hitting an average human head is less of a transfer of momentum than a human head impacting something at walking speed.

Considering that you're wearing a helmet, and assuming that it doesn't deform horribly, you should be okay.
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>>28576053
>.44magnum hitting an average human head is less of a transfer of momentum than a human head impacting something at walking speed.
LMAO let's see your math on that one I will wait

>today I learned that being shot in the head with 44mag is less dangerous than walking into a pole
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>>28575683
>My question is, stopping the round or not, can you even survive that level of energy transfer to your head? Wouldn't it give you a closed head injury?

Sure, heavyweight boxers hit for about the same force as a .44 magnum, which emphasizes that it's all going to depend upon how well it dissipates that impact over the entire skull.

If it can actually retain its shape on the inside, it would be like getting punched in the face.
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>>28575683
>>
>>28575809

>I don't realize that an adult human, PARTICULARLY a fat american, falling on you would actually have more energy than that .44.

Look, it's you.
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>>28576080
500m/s x.012kg = 6kgm/s
Avg human head is 5kg
6kgm/s / 5kg = 1.2m/s
Avg human walking speed is 5km/h or 1.389m/s
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>>28576106
Look, it's you
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>>28576138
Also, this is assuming a perfectly elastic collision, which it would certainly not be.
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>>28576106
Doubling down on what >>28576181 posted and calling you a stupid faggot. Go take Physics 1 at your local community college, now.
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>>28575740
Your opponent's luck shouldn't play a part into how you prepare. Otherwise you'll be stuck with 'what ifs'
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>>28576138
>smug, opinionated faggot spouts the "I don't believe you show me the math I will wait lel" meme
>he actually responds with the math to prove his point
Choice cut, bra.
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>>28576181
How did you turn kinetic energy into a force, unless you're implying the bullet and the person stop immediately.
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>>28576214
and also assuming that the math isn't completely wrong because KE is 1/2 m v^2 not mv
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>>28575683
Not a fan of the edges this has.
Many spots a bullet can get a good hit/grip at instead of having a chance at sliding off.

Also the visor doesn't really give you the best of vision. Would be better with something like pic related.
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>>28576258
Ah, actually never mind. This is assuming the mask isn't penetrated.
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>>28576258
the problem wasn't to find force imparted, it was to find kinetic energy
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>>28576258
You're implying that the energy of a bullet slamming into your fucking head won't give you a concussion.

Are you already suffering from one? This is incredibly retarded.
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>>28576247
see
>>28576264
>>
>>28576264
>momentum
You're an idiot
>>
will wearing a neck brace help?
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>>28576278
Why is the one on the left in Newtons
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>>28576297
To keep your neck from breaking? Yeah definitely.

To keep from getting a fucking concussion because you just got shot in the goddamn head? No.
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>>28576304
They're both in Newtons you nigger. You should also point out that he expressed the numbers in two forms of notation too.
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>>28576307
what about lots of soft spongy padding behind mask
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Guy in my company took a fist sized hunk of metal from an ied to his helmet with out penetration. He was pretty much useless the rest of the firefight and had to be med evacuated to Balance to get his head examed. Major concussion, so they sent him to Germnay to get better.
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>>28576320
Get a bunch of spongy soft padding and run the numbers. Come back when you get the energy deposited into your skull down to about 100N. Good luck.
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>>28576293
You incorrectly assumed momentum was the relevant quantity and not kinetic energy

>>28576304
Should be Nm
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Why are you guys arguing about the benefits of not getting a bullet in the head?
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>>28576328
Medevaced to Balad.

Damn phone auto correct.
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>>28576320

Look up brain damage caused by padded boxing gloves. Just live with your concussion mang
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>>28576338
Because apparently half of /k/ dropped out of High School. Holy shit. This is why stupid shit like ballistic masks actually sell.
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>>28576264
>Momentum
>Energy
Retard
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>>28576332
Tell me how KE is relevant.

Momentum is the best way of estimating what kind of "knock" it is equivalent to. Having that mask take a hit that hard, and transfer the momentum to your face PERFECTLY, is less of a jolt than walking straight into a pole.
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>>28576363
He's not wrong. Momentum is a closed system where acceleration is assumed to happen immediately and so no energy is lost in the system. Energy can be extrapolated from momentum easily because it's just a product of mass and velocity.
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>>28576364
>Tell me how KE is relevant
Oh it's only the measure everyone uses to asses damage to humans and property
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>>28575683
A cowboy collar would go a long way to preventing injuries from hard impacts to the mask, but that's not a big threat from anything that the mask can stop. Most blows would be glancing, reducing the energy imparted from the projectile. Between that and whatever padding and extra weight you're wearing on your head, plus some support and strong neck muscles, nothing this thing can stop is likely to give you a concussion.
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>>28576375
>Energy can be extrapolated from momentum easily because it's just a product of mass and velocity.
Not without additional information (i.e. the mass or velocity of the object in question). Momentum and energy are quite different things - you can't just pick and choose whichever one suits your argument at the moment and just ignore the remainder of physics at play.
>Bullet has momentum and energy
>Bullet hits mask
>Energy is dissipated upon (inelastic or partially-elastic) impact
>Momentum is conserved; transferred into victim's head
Momentum IS the major factor at play.
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>>28576364
Kinetic Energy is the killer here bud. It transfers from the bullet, to the mask, to your face, and the energy has to go somewhere. The energy deposited into that small area by a .44 Magnum will fuck you up, guaranteed.
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>>28575754
What, You get like 5 freebies
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>>28576399
I'm sure Dr Fackler would agree with you.
Oh wait, he'd call you a fucking idiot.
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>>28576328
I'm gonna go out on a limb and guess that he's glad it was on the helmet and not his unprotected face.
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>>28576405
>Momentum IS the major factor at play
But that's wrong. Momentum is Newton seconds. Are you telling me if I press on your forehead with my finger for a week it's going to do the same damage as a bullet?
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>>28576407
>It transfers from the bullet, to the mask, to your face
No, it doesn't, you fucking imbecile.
>the energy has to go somewhere.
Heat and strain energy, mostly.

Seriously, did you NEVER do the ballistic pendulum problem in high school? Inelastic collisions are a thing.
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>>28576428
Are you seriously telling me that this scenario would be a near-inelastic collision?
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Looks lie an evil henchman type mask.
>>
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC155412/
http://www.brainfacts.org/diseases-disorders/injury/articles/2012/hard-knocks-the-science-of-concussions/
https://en.wikipedia.org/wiki/Cerebral_edema
The amount of energy you are absorbing into your cranium is what you would get from being hit in the head with a bat from joe scmhoe. It is a very big concern about whether or not you will survive, you are guaranteed to at least have a massive concussion and have a decent chance of developing a cerebral edema, so better than no mask and the odds of survival are far better than if you don't have a mask but even then I would give you a fifty percent chance at most.
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>>28576428
>Heat and strain energy, mostly
I wasn't aware the amount of energy of a pellet of lead getting a little hot was the same as it slamming into a stationary object at 1000 FPS
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>>28575683

It would suck, but it would probably save a life. By "suck" I mean you'd get a concussion, and possibly neck injuries. In this sort of situation you'd want to be standing in such a position where your neck could move back, and where you can fall onto your back. Even just an inch or two of play would make a huge difference.

What I want to see, is if this thing would work better with an entire neck harness (like the ones NASCAR drivers do) that transfers the energy down into your legs.
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>>28575683
I would have bought one by now, but the fucking plates are held on with magnets.

Nothing like having half you armor explode off your face if you take a spill
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>>28576436
A) Yes, and
B) It barely fucking matters at all in the long run.
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>>28576452
Where the fuck are you coming from. Holy fucking shit, there is no way you're going to come out of getting shot with a mask on OK.
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>>28576444
You would be surprised.
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>>28576452
A) You don't know that and
B) If it was a glancing hit or ricochet, it would be more elastic than inelastic.
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>>28576463
>Where the fuck are you coming from.
Reality, that's where.
https://www.youtube.com/watch?v=W2L8PRl-C1c
>OMG so traumatic, skull fracture fer sher

You fucking idiots have zero comprehension of physics in practical terms. A bullet will never transfer all of it's kinetic energy into a more massive target. It's fucking impossible, if you do the math you'd realize it'd violate conservation of momentum. Fucking lrn2science, dumbasses.
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>>28576479
>A) You don't know that
I DO know that, because the impulse imparted on the target is still fucking tiny whether it's elastic or not.
>B) If it was a glancing hit or ricochet, it would be more elastic than inelastic.
I doubt that. You really think a ricochet is gonna come bouncing back at more than half it's velocity?
A glancing blow would have less impulse overall anyways since we're not talking +v to -v but rather a small change in direction.
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>>28576320
The concussion isn't from a thing hitting the outside of your head, it's your brain bouncing around on the inside of your head. the force transferred into the mask is gonna move your head, whether or not the bullet penetrates it.


I think it would certainly be less than a car accident, but you'd probably want to leave the battlefield for a few minutes.
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>>28576469
Breaking news: Bullets heat to 1100 F when shot??
>>
short answer, no.
might theoretically save you from a .22lr at 500 yards and leave you with parkinsons in 10 years but spare your life. you watch the devtec videos and its a bunch of aspies shooting at bulletproof material in an uncontrolled environment and then exclaiming "look guys, its a success it didn't penetrate! look how cool it is!". they take no consideration of impact dispersion or deflective properties in its design. there are mesh cheek rests on the thing for christ sake. all this is is a pretty little shell to scramble your brain in. hey, at least you might have an open casket funeral.
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>>28575683

I could survive it, you probably couldn't though, pussy
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>>28575683
>>28575701
If you can't see and can't breathe then you're pretty much dead anyway no matter how much protection you have on you. This thing looks like much more hindrance in combat than help. You'd be better off with a clear flip-up visor and standard helmet.
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>>28575683
Ima buy one purely to live out my super villain fantasies
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>>28576542
Fuck off you worthless Weebshit trip! Get the fuck out!
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>>28576542
that's fucking hilarious.

"Satori Komeiji" haha, fuck
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>>28576509
The impulse on the mask is still going to fuck your head up though.
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>>28575861
More like Star-Lord.
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>>28576490
>Links a video of an empty helmet being shot.
Funny. That's not the scenario we're talking about. The deflection and surface area of the section of helmet being shot is significantly different to the flush face of a mask being hit.
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>>28576138
here. Let me explain this shit to you fuckwits.

You're hit in the mask with a 12 gram bullet. It's going about 500ms. (that's a 200gr at about 1640fps).
The total momentum of this object is
500m/s x.012kg = 6kgm/s
Now, after a PERFECT ELASTIC COLLISION, a 5kg object (mass of a head) would be moving at a speed of:
6kgm/s / 5kg = 1.2m/s
Now, the average walking speed of a human is 5km/h, which is 1.389m/s. That tells us that the transfer of momentum from being hit in this mask in PERFECT CONDITIONS is still less than that of the transfer of walking into a pole, and coming to a complete stop (because shit nigger you aren't walking through that pole).

Of course, we know that bullets impacting even solid objects like steel plates don't make elastic collisions. That's why we can safely shoot steel silhouette and not die. In the case of the mask, there will be energy and momentum lost to >>28576428
heat, strain, and fragmentation of the projectile. So we know that even less than this would be transferred efficiently.

It's the same reason people can be shot by .308 in a good lined plate and not give a fuck. You're spreading out something that would normally do a lot of damage into a larger area and wasting most of the energy/force/momentum that would normally be used to damage tissue onto moving the plate and any padding behind it. And before anyone says ".308 will knock you flat!", see
https://www.youtube.com/watch?v=o5f1Fo4r4_I from 1:30
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>>28576577
See >>28576138 >>28576053
And watch the fucking video >>28576490
As long as the energy is dissipated outside your skull and not by shredding tissue inside of it, you might be a bit rattled but you'll otherwise be fine.

That said, who knows how good this thing is at ACTUALLY stopping bullets (particularly in the ocular region).
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>>28576595
An empty helmet has even less mass than an occupied one. If a bullet only knocks an empty helmet a foot or so, a helmet with a noggin in it is barely gonna move at all.
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>>28576659
>As long as the energy is dissipated outside your skull and not by shredding tissue inside of it, you might be a bit rattled but you'll otherwise be fine.
That was my entire issue earlier. I know what >>28576602
>>28576509
is sperging about, and he's right, but that is not the problem here. The dissipation and effects of the impact on your gray matter is what needs to be understood.

>>28576681
Won't fucking matter if you're still rendered ineffective and/or unconscious from the impact.
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>>28576700
>Won't fucking matter if you're still rendered ineffective and/or unconscious from the impact.
Beats getting your head blown off.
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>>28576761
>Become a vegetable and/or shit in a bag forever.
>Die
Which one, friendo?
>>
YOU'RE THAT NINJA
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>>28576769
You also forgot.

>become very concussed but make it back home alive.
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>>28576700
>The dissipation and effects of the impact on your gray matter is what needs to be understood
Really?
Are you serious?

The bullet hits the mask. It wastes a good deal of energy and momentum on getting all fucked up by strain as it deforms the mask, deforms itself, sends fragments in other directions (protip: make sure your neck is covered if you wear one of these masks), and from friction.

Then, whatever is left is transferred through the mask, to the face. This takes time, and uses up more energy; you're doing work to move the mask and compress any padding.

After that, whatever is still left is transferred first to the hair, skin and then the skull. Whatever is left after that is transferred to your brain.

And you're arguing that this is more damaging than a collision with higher momentum transfer that happens DIRECTLY to the head, with no mask or padding inbetween, which people almost always walk away from a little bit dazed and swearing at most.
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>>28576801
Well, I guess I'm just up late then. Something about this whole idea still sounds fucking retarded but the math is there. Time to complete the stepladder like good engineers and get a youtube video put together, strap some masks on, load up some 9mm 124gr, and see how many times we can recite the alphabet before and after shooting ourselves in the face.
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>>28575740
>>28575725
I am not and will not consider buying one, but no matter how hard you prepare some limp dick that has no clue what he's doing is going to fuck you up in the way you never expect. They're not going to shoot accurately, they're not going to prepare. They are just going to walk up and shit on everything you respect; that includes your training.
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>>28576820
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>>28576832
What? Do you not trust the math? Surely you've covered everything, right?
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>>28576847
>>
>>28576820
>>28576832
>someone admits they're wrong
>smuganimeface.png
Come on now.

I'm "momentum-anon", and as much as I'd like to "ur a faget" about it, I'm just glad that someone, for once, had a little bit of grace when they decided they were wrong on 4chan.
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>>28576860
pic related

>>28576866
Yeah. I'm just off my Addy and it's been a long first week of classwork. Ironically the same shit we're throwing poo about. I just felt like something was missing the whole time, a part of the system that'd be fatal to the wearer, etc. If the math is there, it's fucking there.

Only thing I'm not seeing on YouTube are videos of people wearing this on live-fire tests, that's why I'm so goddamn critical.
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>>28575721
Pretty much, unless you draw the short straw and are first in line for a breach you probably would be at a loss if you actually wear this.
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>This fucking retard thinking that a bullet to this helmet is going to cause brain damage

Newton's 3rd Law

The bullet's impact will hit no harder than the recoil the shooter experiences. Unless the gun being fired regularly damages the shooter's bones and soft tissue from recoil then the person being shot wearing this helmet; provided there is no penetration, will be fine.
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>>28576875
Well, the whole thing hinges on it working correctly.

If the mask deforms too much and crushes your face then all bets are off.
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>>28576875
>Only thing I'm not seeing on YouTube are videos of people wearing this on live-fire tests, that's why I'm so goddamn critical.
Well there is atleast one video, but the gun used was a shotgun and not a slug was used.
https://www.youtube.com/watch?v=l9W164GvlYs
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>>28576899
how about CQB?
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>>28576901
Put the butt of a 12 gauge up against your forehead and pull the trigger, do it faggot

also
>impulse
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>>28576903
Yeah I didn't mention deformation cuz I didn't want momentum-anon to accuse me of goalpost moving. NIJ says 44mm or less I believe.

>>28576904
>scattergun
Yeah, not what we're after. Gotta wait for someone brave enough to try a 12ga slug or something like .45/70.
>>
>>28576912
Still would be better off with having a full range of vision if you aren't the guy with a shield and a mask spraying the room and soaking bullets headfirst.
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>>28576426
No, but if you moved your finger really fast it would. You've gone and introduced impulse to the problem now.

>>28576517
Nope, that assumes translational energy becomes 100% heat during the firing. However, the math is correct. Purely in terms of equivalent energy only, not in context. However, during an inelastic collision a significant amount of energy might be lost as heat. Other might be lost as mechanical energy to fragment the objects.

>>28576602. <this

How much does this thing run?
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>>28576917

It's going to hurt but any damage will be minimal and comparable to the brain damage football players endure when tackled i.e. it would require many, many, many such impacts.

>impulse
The word you're looking for is SHOCK or IMPACT. There's no such thing as an "impulse" TBI injury you fucking retard.
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>>28576974
>moved your finger really fast
>introduced impulse
Nigger the units of momentum are Newtons and Seconds.
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>>28575683

There has been ppl who been shot in the head, the bullet skid across the skull and they were fine. Humans are weird in that way...we can die so easily same time we are capable of surviving some shit.
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ITT: cool facemasks
i want this to be real
>>
A lot of idiotic arguments in this thread.
In Iraq I saw guys get hit in the head with shrapnel and even an errant pistol round, but survive thanks to their helmet.
Neck injury? Yes. Brain injury? Yes. But most importantly? ALIVE without permanant injury.
So in short, as a Veteran I would wear this in combat if given a choice. But it would become a hinderance as soon as it got hot.
Most common injuries in Iraq/Afghanistan
>heat stroke/heat exhaustion/heat cramps
>Wearing a mask will increase those issues.
So it has better be used in cold climates or have a cooling fan and have a way to drink water
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>>28575741
that is good idea :^)
>>
>>28575683
I look forward to this tech reaching it's peak so we can have gun fights for sport like gun fencing and duels in general.
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>>28575773
poast
>>
>>28575736
real flashlight with white/red and lo intsi mode on one side. IR flashlight on the other. i can dig it.
>>
>>28576238

Yes it should, are you fucking retarded? This helmet serves the same principle as all other body armour. You wear the shit in case someone gets a lucky hit on you, you cunts will semantics on every fucking thing you say.
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>>28576080

https://www.youtube.com/watch?v=5BaOvM9jXKg

>>28576138
>>
>>28577489
> We mandalorians now

Also how is he supposed to use those NVGs?
>>
>>28575683
As soon as the creators put one on their heads and take a .44 to the face, I'll give a fuck. Until then it's pure gimmick bullshit.
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>>28578218
lol dunno
we star wars nao
>>
>>28575683
Has anyone tried to make a climate controlled full-face helmet with an integrated port for an air supply?

Because I really can't see how you could operate in something like this mask without being smothered while you get heat stroke. Where does air get in?
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>hurr itt'd knock ya right down
>cuncusshon fur shur
>whip yer head round like muh trakter tiire

How does /k/ still not grasp the concept of impacts against hard surfaces?

Why does most of this board think getting shot in a hard plate with zero backface deformation feels like anything beyond a tap?

After over a decade here, I hate you all.
>>
>>28580103
>I don't understand anything about shock mechanics and energy transfer.
>>
>>28580126
>implifuckingcations

https://www.youtube.com/watch?v=6x59iN4KMz4

But please, go on and tell me all about how some marine totally told you about the time he took an AK round to the plate and it totally like knocked him down and broke his ribs, man.

Does the rifle knock you the fuck over when you fire it?

No?

Why don't you stick the muzzle up your asshole and try it out?

Please never breed.
>>
>Enclave here, why isn't your video feed working?
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>>28580288
>enclave
Ho Lee Fuk
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>>28580328
That's not fucking enclave armor god damn it Bethesda that's the BoS armor from tactics fuck me.
>>
>>28575683
If it's correctly designed there is no "energy" transfert per say, the energy is spent mostly deforming materials.

You'll have a shockwave that is dependant on the materials used and the design of the helmet. Shouldn't be massive tho, and varies with the caliber.

The only thing you can be sure of is the conservation of momentum, basicaly imagine the recoil force of the gun applied to your head. It's very low, a .44 will hit with less force than a punch, but it's not pleasant.
>>
>>28580288
>>28575683
We cog now
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>>28575683
if it comes with a piece that can stabilize the neck you will be fine. This will stop the brain from rattling. As a boxer when we get hit its usually our head jerking that causes a concussion or knockout.
>>
>>28576426
If the bullet doesn't penetrate your skull, sure.
>>
Take a 44 magnum revolver, put it against your forehead, and pull the trigger. It would be uncomfortable but not that bad.

And in case this isn't obvious, face the muzzle away from your head.
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>>28580534
>this will stop the brain from rattling

First off, you're dead wrong.

Second, you're still dead wrong. The force of a bullet impact that fails to penetrate is going to impart FAR less force than required for any sort of injury. In fact, it would hardly even move your head at all.

>>28580641
THIS THIS THIS THIS

If it doesn't BREAK YOUR FUCKING HAND/ARM/SHOULDER/DICK to fire it, the projectile isn't going to somehow MAGICALLY GAIN MORE ENERGY until it impacts something.
>>
>>28576282

Do you think the recoil of a handgun is enough to give you a concussion? Because the force of it impacting something is going to be less than that, unless your projectile is magically gaining energy as it travels.
>>
>>28575807
http://www.ops-core.com/Gunsight_Mandible_Ballistic_H_P95C20.cfm

Which is better ?
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>>28580764
>site won't let you on if you don't have flash player
>on mobile
Can you screenshot it real quick.
>>
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>>28580103
>>
>>28580764
The Crye has substantially higher protection and is cheaper.
>>
>>28580681
How am I dead wrong? You dont think when an object hauling ass hits you your body isnt going to jerk in some manor. Let me put a helmet on you and punch you in the face your neck will still jerk back. Lmao confirmed for never playing contact sports.
>>
>>28580864
Your argument it retarded, comparing apples to oranges.
Kind of reminded me of that "if you shoot a duck I'm scared of ballsack" meme
>>
>>28580837
Is it? Is it really, faggot?

Go watch the fucking videos of the wops taking 7.62x39 to the chest plate at less than a foot, without hardly a flinch.

>>28580864
Because you are fucking dead wrong.

This isn't a fucking safety laying you the fuck out. This is a relatively light projectile impacting a relatively broad surface that it fails to penetrate or dent. The entire fucking plate takes the force of the impact, which equates out to be fuckall for felt impact.

The impact from 7.62x39 to a hard plate is SUBSTANTIALLY less impact force vs a human fist thrown by even a complete non-fighter.

Does a .45 derringer blow your hand apart and break fingers and shit?

No?

So WHY THE FUCK would you think that same round is somehow capable of giving you any sort of head injury?

Kill yourself.
>>
>>28580885
>Object travels and hits solid object that is attached to movable appendage.
>The forward energy hits solid object causing the energy to spread and disperse it still has forward moving potential.
>The appendage takes some energy as its distributed through the mask (similar to how you take the energy from a cars speed, weight, etc in a car crash)
>Whips neck back causing brain to rock

Physics 1 & 2
>>
>>28580908
>Thinking ~ 13lbf of energy will feel like a tap
>being this retarded
>>
>>28580908
You know what happens when a bullet hits a vest plate? It causes impact and force and knocks you off your feet. In cases causing broken ribs and internal damage. Lmao I cant believe people are this stupid.

>>28580930
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>>28580816

With the Crye Chops, you get protection against 2-4gr fragments moving 1000fps faster than the Gunsite mandibles. 200 more fps against 9mm, and unlike the mandibles, has level IIIa protection against .44 magnum. It also costs $260 vs $456.
>>
/k/ - physics
>>
>>28580931
~13lbs of force
Yeah, that is a fucking tap. The average human can throw a punch that measures in the hundreds of pounds.
>>
>>28576585
You meant Sith-Lard right?
>>
>>28580908
THIS IS A SMALL CALIBER SHOT WITH VEST

https://www.youtube.com/watch?v=6JLsDLwZlq4
>>
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>>28580975
>soft armor
Just stop.
>>
>>28580943
>You know what happens when a bullet hits a vest plate? It causes impact and force and knocks you off your feet. In cases causing broken ribs and internal damage. Lmao I cant believe people are this stupid.

I can't believe retards still believe this meme

https://www.youtube.com/watch?v=hdqaM-zpOQ0
>>
>>28580994
When a bullet hits something the energy spreads thats the point of the plates. When energy disperses it can still cause damage. Ask any vet who has been hit while wearing a vest how it feels. And the vid is the same concept small plate small cal. still injury. Are you this retarded srs.

>le insult while i post anime pics from mummys basement
>>
>>28580975
>Soft vest
>Doesn't even knock him visibly at all
>Deformation of the vest causes point-injury and bruising
>He flinches from the pain half a second after impact
Suuuuure, nice "proof."
>>
>>28575838
if shooting those guns won't break your wrist, taking the bullet won't break your neck.

You might hurt your neck temporary, but the mask is not bolted to your face, impact would tear it off and transfer energy in many directions including your face.

Bullets don't fucking get random energy during their travel, they lose it. Quite fast.

Your head moves on a neck and your mask wiggles on your face.

As long as your head is not bolted down and the mask bolted down on it with 0 wiggle room, you'll propably end up with a black eye or a broken nose and sore neck at worst.
>>
>>28581010
Shell casing does not even cling when it hits the ground.

>discarded
Gonna go with the people who came into medic after being hit with broken ribs and internal bleeding.

U LIAR U WRONG
But I have seen it
NO LOOK LE VIDEO FROM YOUTUBE DAT COULDNT BE ALTERED
But in combat they get shot they have issues
SHUT UP YOU POOP

Back 2 reddit
>>
>>28581010
To be fair, blunt injuries and broken ribs can still occur if the plate is sufficiently deformed or spalls. But it's not a concussive injury like the fudd-tier retards in this thread are parroting.
>>
>>28581030
https://www.youtube.com/watch?v=lRTwqV0ybwc
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>>28581055
Did you even watch the video? You can clearly hear the casings when they bounce.
>>
>>28580944
But I don't get to look like I'm from the future with that :(

>>28581055
You can clearly hear the casings moron.
>>
>>28581066
If you get shot in the face point blank with that helmet on that your neck wont snap back?
>>
>>28581084
>>28581074
Retardation cant be fixed. Go serve your country and take one then come talk to me.
>>
>>28581098
Tank u 4 ur srvic
>>
>>28581098
just cause you're in the army doesn't mean you understand how your equipment works.
Being in the army just means you didn't get into higher education.

Civillian specialists in many cases know better than the avarage grunt on the ground.
>>
>>28581098
>calling others retarded when you can't even hear the obvious as fuck cling the casings make
>>
>>28580975

You're confusing soft armor with hard plate armor. Soft armor needs to deform in order to capture the bullet, which can cause blunt trauma. Hard armor tends to not deform when stopping a bullet, so blunt trauma isn't a problem.
>>
>>28576450
Or shift to obscure your vision
>>
>>28576080
GOD DAMN you're fucking stupid. The amount of momentum something has is completely different from how "dangerous" it is.

A fucking Honda Civic rolling along at 1 mph has THOUSANDS of times more momentum than a .44 magnum. That doesn't mean it's going to kill you when it hits you does it dipshit?

fucking retard.
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The best defense is not getting shot. But how do you do that? By staying in school, you dummy.
>>
>>28581363
If you are immobile relative to the civic during the time frame then yes it would kill you.
>>
>>28581363
What?

The Honda civic is more deadly, but because its so slow you can move out of the way.

The bullet is less deadly, but going so fast that your body cannot get out of the way.

More momentum = lethaler
>>
>>28575683
Your head will be ok, just a concussion. Face will be all fucked up though.
>>
>>
>>28579984
there was a system in the works, Army dropped it after everyone who wasn't a POG in a parking lot testing it called it retarded, heavy and useless.
>>
>>28581456
I'm not sure you understand what the word "deadly" means.
>>
>>28580166
>implying he wasn't wearing a trauma pad

There is a difference between an impact on a hard plate with zero deformation (which is the worst case scenario when considering shock trauma) transferring to a torso, and the same impact transferring its energy in a trauma plate, then a torso.

>Does the rifle knock you the fuck over when you fire it?
Again, it's shock mechanics, and absorption over distance and time. The rifle doesn't knock you over, because you are movable in space. It pushes your shoulder as it travels backwards.

If you were to put your shoulder between a high-caliber rifle and a non-deformable wall, it would be crushed.

The reason marines don't get their ribs broken is because they have a trauma pad, or standalone plate to absorb the shock. In the case of the mask, if there is no deformation, all that energy is directed towards a momentum gain for the mask and your head. The problem is that your head+mask has little mass, and thus requires little inertia to move, while your torso does. Your head will be pushed violently, while your torso won't. Consequentially, your neck would get wrung, which can cause a lot of damage.

Getting shot in a plate won't knock you down, but it can cause shock trauma if it's not properly absorbed. It's way more than a "tap".
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>>28576904
BALLS OF STEEL
>>
>>28580908
You fucking retard.
You think momentum is all that matters?

Just ask your teacher about "shock mechanics" when you're done with your homework.
>>
>>28575683
I'm not gonna lie I kinda want. Not for any real protective value though.
>>
>>28575683
If you did get hit in the head by a .44mag you'll probably get knocked out still even if it didn't kill you or fracture your skull
>>
>>28576340
>that image
I remembered something about people complaining on how the artist sucked at drawing an AK when it was actually an AN-94.
>>
>>28580103
/k/ isn't a decade old.
>>
>>28575721
Kek. But still kinda cool mask
>>
>>28576282

You know the force you feel when you shoot? That's the force with which the bullet comes out of the barrel....equal and opposite reaction and all. Of course, that force is imparted on a much smaller object when talking about the bullet, but that doesn't change they fact.

If the recoils from a would e enough to knock you out if you had it up to your head, then you would be right. But you're not.
>>
Ninjaneer here. Let's do some MATH, NIGGAS!

Let's call our .44 magnum a 250gr bullet at 1,600 fps.

That's p much 1.2 grams at 488 m/s. This gives us roughly 143 joules of energy.

According to google, the average human head weights 5kg. Going the other way, that gives us a velocity of 7.6 m/s. Assuming this energy is transferred in .1 seconds (it'd be less), that's 76 m/s^2.

That translates to 7.75 G's.

According to https://en.wikipedia.org/wiki/G-force an average human can take 5 Gs before losing it. According to http://www.braininjury.com/injured.shtml you can take between 10 and 50 Gs without getting brain damage. The varies from person to person, obviously.


So, in conclusion, you'd survive it, more than likely. You probably wouldn't even have brain damage. You MIGHT pass out, though. Probably not enough duration, TEE BEE AYCH, FAHM. It'd hurt like motherfucker but you'd be alright.
>>
*This looks like the mask from Dishonored desu senpai
>>
>>28575683
>>28576272
>literally too edgy
>>
>>28576602

>"Rich, I'd like ya to shoot me again"

wew lads
>>
>>28581043
>As long as your head is not bolted down and the mask bolted down on it with 0 wiggle room, you'll propably end up with a black eye or a broken nose and sore neck at worst.

Plus fucking 1. This thing could definitely work. Whether or not it's worth the weight and the potential respiration/perspiration issues is a separate concern.
>>
>>28575838
>this fuddlore again
>>
>>28576282
It won't, retard. Do you understand basic physics?

Armour works by distributing the energy of the projectile evenly over a large area, preventing penetration. You're only feeling the same energy as the recoil of the weapon (a little less, actually). That isn't going to fuck you up.
>>
>>28585329

Holy fuck. I feel bad for the company that employs you to be an "engineer"
>>
>>28585661
MD/PhD in trauma/emergency medicine and 15 years experience as first responder in large city here.

Depends on padding like trauma pad shit discussed above. Impulse (F*t) into shooter's shoulder and your face is the same, but force felt is dependent on how long total momentum transfer takes. Padded shit = takes longer = less force felt. Total force = P*A, so what you mentioned is pressure. High pressure and short times kill. This is what leads to hydrostatic shock inside of you that is actually damaging. Another post above talks about Gs, which is simply just acceleration. This isn't correct because we are virtually continuous "fluid" mass. What's better is to think about the fluid acceleration (basically waves) inside of people. The whole head won't have the same G acceleration and the reason why people survive such high Gs is because WHOLE head accelerates. What makes bullets more brutal is that brain tissue regionally accelerates differently as shock wave moves through (i.e. being in a swell on an ocean wave makes you accelerate more than being in the top or trough).
This is what tears tissues, makes you have brain bleeds, etc.
>>
>>28575683
You'll be coming out of this unconscious and with at least a concussion. You'll most likely need a hospital visit
>>
>>28585667

Care to point out what's wrong there or are you just shitposting?
>>
>>28585970
>>28585957
I explained why it was wrong above. Basically, fluids accelerating and solid mass accelerating are different beasts. Most medical problems due to gunshots and trauma are due to fluid "shockwaves" moving through sensitive tissue.
>>
>>28585970
To clarify, imagine the differential compression and expansion of brain tissue as shockwave moves through. This literally tears the tissue, compared to simple acceleration which only compresses the WHOLE body. This isn't as dangerous, although it's still very bad.
>>
>>28583884
>A FUCKING PULLEY SYSTEM
>>
>>28585997
>>28586015

Well sure. I mean, we could have gone WAAAAY further with the math. We could have done fluid mechanics and rotational inertia but shit, man. It was just a basic calculation with real numbers. The physics and math were still sound.

If someone would like to do a more complete analysis and demonstrate the math, I'll sit here and wait.
>>
>>28585970
Engineer here, I'll answer.

>Assuming this energy is transferred in .1 seconds (it'd be less)
If it's less time to absorbe the energy, it's more Gs.
If it's more Gs, it's dangerous.

You got the logic backwards, you retarded engineer.
>>
>>28581417
AAA, A+, 5-Star post.
Ya dingus.
>>
>>28575683

This thread has way too much discussion about bullets hitting your head

Simple question:
If you did get shot in the head, would you rather be wearing this or just get shot in the head?
It's a "no brainer".

I don't think the main idea of this is to protect you from getting shot in the head though. It MIGHT save your ass, but even helmets get penetrated by certain calibers.

What it would be good for (and what most eye protection is designed for) is for saving your ass from getting hit with shrapnel/spall/fire/etc.

Basically anything that could fuck your world up on a battlefield that is not a bullet. I think this mask would be pretty shit for dismounted infantry.

It might actually be good for vehicle crew members though, particularly light vehicles that are most likely to sustain damage resulting in shrapnel/fire getting in the crew compartment.

If I had to ride around in an MRAP or something similar in a war zone, and I had the option of wearing this, I probably would. Would take it off and stick with a normal helmet outside though, it would get in the way too much on the ground.
>>
>>28580481
IM fine with this. did you see how big those fuckers were?
>>
>>28576901
Someone doesn't own a gyrojet
>>
>>28586115

Yeah, no shit. I also didn't hold that many decimal places. I was doing calculations off the cuff. If you'd like to find the length of a .429 in bullet and the time it'd take for that length to travel from nose to tail, be my guess. I didn't make any statements about change in velocity over a change in time. So please, point out to me where my logic is backwards, you unemployed engineer.
>>
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>>28576904
>MFW he stuck his head out after that.
>>
>>28586212
I just explained it to you, fucktard. The energy is transferred in much less than 0.1s. That means that the Gs are HIGHER.

Purposefully overestimating the time it takes for the shock to be absorbed severely underestimates the amount of Gs. Thus, this renders your calculation invalid, because you didn't take the "worst case scenario". You thought you were being conservative, but you weren't.

You didn't prove shit.
>>
>>28575683
Strap a 44.mag to ur head and fire it. The recoil felt cant be anymore than the energy felt when being hit.
>>
>>28586307
>The recoil felt cant be anymore than the energy felt when being hit.
Equal energy =/= Equal shock on impact
>>
>>28586320
It will be more or less the same. You wont get any concussion or anything of the sort if the helmet is on properly.
>>
>>28586272

No. Fucking. Shit.

I didn't say it'd be more or less. I didn't say it was the worst case scenario. I didn't say anything about it other than it'd take less time than I used for my off-the-cuff estimation.

Are you a first year student or did you just go to school in Arkansas? Maybe you are just a cousin of Dr8co and need me to do this in Spanish for your inbred ass.

Let's go with 0.81 inches since that's what I pulled up quickly for a goddamn 220 grain round. That's 0.0675 feet since you obviously can't do the math seeing as I gave you the opportunity to do the math and prove me wrong.

Now, please go ahead and finish up with the kinetic energy and acceleration equations and show us all how good you are. Let's see the massive difference in acceleration that 250 grains transfers to a 5kg mass in a much smaller time frame.
>>
>>28581084
That's the point. Not only are they better, but the chops don't make you look less like cyborg ninja and more like a real human bring.
>>
>>28576238
>Otherwise you'll be stuck with 'what ifs'
oh so that's bad
no one should prepare for anything in that case
>>
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>>28576904
Good fucking lord. I knew the MTEK sturdy models were supposed to help you survive a gunshot to the face, but I didn't think it would have looked that fine. Granted, the dude looked like he was very well braced and the energy was absorbed fairly well, but still, holy fuck.

>>28586590
>not wanting to be a cyborg ninja guntruck gunner

Shiggity diggity.
>>
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/k/'s resident airshitter here

Devtac Ronin makes these masks, literally, for Airsofters. They then added the NIJ rating for shits and giggles to justify their obscene price.

The mask, all things considered, is really made well with good retention straps. It has fans to circulate the air inside the mask, preventing fogging and keeping your face cool.

Why it's a dumb idea - It doesn't cover the entirety of your head. Your rear is completely exposed. So rounds or shrapnel coming from behind will still fuck your day up unimpeded. Also, as mentioned in the thread already, the mask has a lot of grooves that would prevent a bullet from deflecting properly and instead would just transfer the energy into the mask.

Otherwise the idea isn't flawed or super keyboard commando. It just seems like a helmet with the typical GIGN style clear plexiglass mask is better overall - which is the system I would choose if I ever had a choice.

Pic related - Taiwanese army with their ballistic face masks
>>
>>28586720
>UCP Helmet cover
>1 hole nvg shroud
>someone went to the trouble of installing some sort of rail system, which doesn't host accessories, lights or other cool shit - but instead it holds some dumb face mask

That guy better be some sort of door / roof gunner or some shit
>>
>>28580943
>You know what happens when a bullet hits a vest plate? It causes impact and force and knocks you off your feet. In cases causing broken ribs and internal damage

jesus christ are you kidding me nigger

https://www.youtube.com/watch?v=19ldkMLJEYw

>guy getting shot point blank with an FAL, standing mostly with only one foot on the ground for demonstration
>"It really didn't feel like much. Much less than a punch."
>>
>>28586102
Did you even read my explanations? Your physics weren't sound in this context because it's not a solid body accelerating and you have to consider continuous deformations of the brain. If the head was a solid ball, then your physics is sound.

I'm saying you have to consider your brain/soft tissue as a soft fluid mass compressing and expanding rather than thinking about it as a solid ball that is moving uniformly.

There's also nothing to do with rotational inertia in this case unless you're mentioning the torque due to bullet hitting or bullet spin, which is a SUPER minor effect compared to brain being forced to be the medium of high energy waves.

Read and think before you talk.
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>>28586970
>>
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>>28586525
>I didn't say it'd be more or less.
>I didn't say anything about it other than it'd take less time than I used for my off-the-cuff estimation.
Yeah, ok.

>I didn't say it was the worst case scenario.
And yet you used it to somewhat explain that there wouldn't be damage.

>Do the math for me
Jesus Christ, you should be ashamed of calling yourself an engineer. I’ll play tag. You wanted to prove that it couldn’t do damage. I’ll prove that it can take damage, even with damage-minimizing assumptions.

Since a G can be approximated to 10 m/s^2 (it's 9.81) I'll use metric.

From this video, it is visible that bullets that deform on impact are not significantly slowed down as they are deforming (probably soft points, which is a damage minimizing assumption, since a hard bullet wouldn’t absorb as much energy through its own deformation). Thus, from bullet length and impact velocity, we can estimate the time it took for the bullet to transfer it’s energy to the mask.
https://www.youtube.com/watch?v=QfDoQwIAaXg
While it is true that the bullet deformation removes quite a lot of that energy, I’ll just ignore it for now, and remove some of that energy later.

Overall length is 41.89mm, case length is 32.64, thus the part of the bullet that protrudes is 9.25mm. From related picture, I’ll guesstimate that the rim-to-tip length is about a third of the overall bullet length. Since it’s approximate, I’ll just say that the bullet is about 30mm long.

I’ll start by using your own numbers (1600 FPS or about 488 m/s), and with a 250 gr (or 1.6 gram) bullet. Since the velocity is still reduced at impact, I’ll say that the velocity is 1400 FPS (or 426 m/s). This gives a kinetic energy of 1450J. Recall that the bullet deformation takes some lot of that energy, so I’ll conservatively assume that the energy transferred to the mask is only 700 joules. Assuming a 5kg mass, this kinetic energy translates to a ~8 m/s velocity.

Cont' (1/2)
>>
>>28586867
He's a 50 cal gunner. We had a thread on it way way way back
>>
>tfw people on /k/ try to out physics professor each other while not understanding something as simple as joules

From someone who has actually taken a bullet to the helmet, everyone is full of shit
>>
>>28586838
> It just seems like a helmet with the typical GIGN style clear plexiglass mask is better overall - which is the system I would choose if I ever had a choice.
Hell, the Polycarb they use in ballistic eyewear can stop a 12g 00 pellet, that's more than good enough for full-face protection considering a kevlar helmet can't stop rifle rounds either.

Maybe shift to a skullbucket like this that integrates a hud for NETT Warrior or whatever it will be called, and the battery can run a low-power ventilation system and modular earpro/radio headset, all either integrated or connected via a single coil cable to a low-profile pack.
>>
The bullet isn’t entirely deformed, the base is still there on impact, so the travel the bullet goes through as it is deformed isn’t the full 30mm. Assuming 20mm of travel at 1400 FPS (or 426 m/s), the bullet transfers all of its energy within 0.02/426=4.7E-5 seconds.
That’s pretty low, but you can check this paper to verify that it’s indeed the correct order of magnitude.
http://www.altairatc.com/india/previous-events/2012/papers-2012/RNL-NA-01_Simulation_of_Bullet_Impact_on_Bullet_Godrej.pdf

Thus, assuming we have that 5Kg mass reaching a 8m/s velocity in 4.7E-5 seconds, and acceleration being velocity change over time, we get 10/4.7E-5=170 000 Gs. Is that unrealistic? The wikipedia page for G force indicates 190000Gs for a 9mm Parabellum for peak acceleration in the barrel (and 60 000 Gs for average along the barrel, but that’s over a longer distance and time, so it’s much lower than the shock we are considering). Again, I’ll be nice, and assume that the final velocity isn't 8m/s but 5m/s. That mask is experiencing at least 100 000 Gs. Since the mask and a human head aren't solidly linked, and since the mask will take additional time and travel to transfer the energy to the head, I'll be EXTRA NICE, and remove 3 orders of magnitude.
That's still 100Gs. (Which is survivable if it's a peak acceleration, with a very lucky person)

So you can take those ridiculous orders of magnitude of yours and shove them deep in YOUR ass before you call yourself an engineer again. My numbers are probably wrong, because of a lot of assumptions, but at least I got the physics right. A bullet impact, nor it's consequential acceleration to a human body part, is nowhere near 7Gs.

I'll let bio experts deal with the energy transfer from the mask to the head, then to the brain.
>>
File: k doing physics.webm (1 MB, 634x360) Image search: [iqdb] [SauceNao] [Google]
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>>28587438
>I’ll start by using your own numbers (1600 FPS or about 488 m/s), and with a 250 gr (or 1.6 gram) bullet. Since the velocity is still reduced at impact, I’ll say that the velocity is 1400 FPS (or 426 m/s). This gives a kinetic energy of 1450J.

1.6 grams... 426m/s... you think this is 1450J. Really? REALLY?!

ONE HALF FUCKING M V SQUARED AND YOU THINK ZERO POINT ZERO ZERO ONE SIX KILOGRAMS TIMES FOUR HUNDRED TWENTY SIX METERS PER SECOND IS OVER FOURTEEN HUNDRED JOULES?!

That's it. I fucking quit. I'm not doing this any more. You're not even trolling. I'm going to fucking bed. You make me ashamed that I even read this site. You're not an engineer and you can't do simple math.

I hope you step on a Lego.
>>
>>28587642
My bad, calculator typo, missed a zero.
145J
Assuming that the impact removes about half to that energy, that's 70 joules.

70 joules of kinetic energy to a 5kg mass yields 2.64 m/s.

Assuming the same time scale (4.7E-5), you get 2.64/(4.7E-5)=36170 Gs.

I missed a zero, but you missed physics, and you're still a retard.
>>
>>28587438
>>28587640

Hey, not the same guy but you should probably ask for a refund on your degree. Just saying, bruh.
>>
>>28587728
I missed a zero, big deal.
I fixed it: >>28587714
>>
>>28587714
FFS, it's getting late and I keep fucking up my math.

145J, assuming deformation takes about half, that's 70Joules, which yields 5.29m/s of velocity with a 5Kg mass.

5.29/(4.7E-5)=112765Gs

Finally.. Jeez, fuck doing math on a Sunday evening.
>>
>>28581043

But that is not how it works fagmaster, when you shoot a gun the energy is transferred over a greater length of time. When you get shot the energy is transferred nearly all at once.

It's very possible your neck could end up broken.
>>
>>28587749
>>28587803
If you didn't see anything wrong with misplacing a fucking thousandths you need to go back to school.
>>
>>28587714

36,000 Gs. That's your final answer? Again, I'm the second guy, not the one you were arguing with but you think a 44 mag round dumps 36,170 Gs of acceleration into a human head. Yeah? That's where we're going? Lol, k.
>>
>>28587438
>>28587640
>>28587714
>>28587803
You clearly don't know how to use your calculator.
But the physics are correct. Bullet peak accelerations have huge G values.
>>
Holy shit, you dumb niggers are STILL arguing about this?
>>28587714
>70 joules of kinetic energy to a 5kg mass yields 2.64 m/s.
>Momentum magically appearing out of nowhere
Looks like YOU'RE the one missing physics, pal.

Momentum HAS to be conserved. Period. So unless the helmet is made of explodium causing a hyperelastic collision, with the bullet bouncing away from the impact with twenty times the velocity it had before the impact, there's no fucking way that it's going to knock a 5 kg head to 2.64 m/s.
>>
>>28587854
Well, there are a lot of assumptions, like the mask being non-deformable and non-movable, which is a huge assumption, because it'll make the Gs skyrocket.

Assuming that the mask moves only 0.5cm, and that the head, in turn, moves like only 1cm would reduce the Gs quite a bit. Physically, I'm expecting far lower values, but nowhere near 7Gs for the mask. That's ridiculous.
>>
>>28587897
I didn't conserve the 145J of momentum, because I assumed that the deformation of the boulet would consume some of that energy.

The calculations are otherwise correct (corrections included, of course)
>>
>>28587926
I meant bullet.
>>
>>28587926
>The calculations are otherwise correct (corrections included, of course)
Great, you (eventually) made correct calculations of a physically-impossible scenario. Congratulations.

Now try again, taking conservation of momentum into account.
>>
>>28587902
Also, the velocity isn't 2.64m/s it's 5.39m/s

5*0.5*5.29*5.29=70J
see
>>28587803
>>
>>28587983
It would only render the final G force values higher, because I'd be assuming 145J instead of 70J. You sure?
>>
>>28587846
>Implying you never missed an order of magnitude when you were doing calculations with a calculator.
>>
>>28588051
I have and if I had to go through work and type it out and explain it like you did I would catch it unless incredibly drunk of tired. Go to bed, you have remedial Algebra tomorrow.
>>
>>28588004
>Still working in Joules after I directly told you that MOMENTUM must be conserved
You literal fucking retard.

>426 m/s * 1.6 g = 0.6816 Newton-seconds of momentum
This MUST be conserved within the system. Mechanical energy (i.e. your precious fucking Joules) may or may not be conserved, but momentum ABSOLUTELY MUST be conserved.
>Inelastic case: Bullet embeds in helmet
>Final velocity of head+helmet+bullet: (0.6816 N-s)/(5001.6 g) = 0.1363 meters per second
That's IT. In an elastic collision (i.e. when mechanical energy IS conserved), the velocity of the head would be just under twice that, and MOST of the kinetic energy would be carried by the bullet bouncing away at over 400 m/s. But for YOUR result, in order for *momentum* to be conserved, the bullet would need to have a final, post-bounce velocity of (negative) SIXTEEN THOUSAND, eight hundred and fourty(ish) meters per second. And as you can imagine, having the bullet bounce back with that much velocity would require a metric fuckload of energy manifesting out of thin air.
>>
>>28588120
>I had to go through work and type it out and explain it like you did I would catch it

I missed the mistakes exactly because I had to write all that crap, juggling between my scribbles, my calculator, and my keyboard.
Not that I'd not make mistakes in a more favorable environment, though.

Regardless, the calculations go like this:
=>Bullet velocity and mass
=>Bullet kinetic energy
=>Impacted body mass + distance/time to absorb bullet kinetic energy
=>Acceleration

If anyone has better assumptions or a better method to estimate shocks I'm all ears.
>>
>>28588215
>In an elastic collision (i.e. when mechanical energy IS conserved)

Sorry, tired. I was fixating on keeping kinetic energy, since conservation of momentum would imply no bullet deformation.

Ok, if I keep momentum, then bullet momentum is 0.0016(Kg)*426(m/s)=0.68 Kg.m/s
With a head of 5 Kg , conservation of momentum would yield 0.13 m/s.

If I choose conservation of momentum of conservation of energy, the head will reach a velocity of 0.13m/s.
If I keep the assumption that this occurs in 4.7E-5, then the G forces are 2765Gs.

Still pretty high.

Though I recognize the interest of momentum over kinetic energy since it you can neglect bullet deformation.
>>
army of two is now a real thing
>>
>>28588368
>Sorry, tired. I was fixating on keeping kinetic energy, since conservation of momentum would imply no bullet deformation.
Nevermind, this is bullshit.
Jesus, disregard.

Elastic=conservation of kinetic energy
Inelastic= use momentum
>>
>>28588215
So for those of us that don't understand what you guys are arguing, what's the final verdict? Would the impact cause head trauma?
>>
>>28588392
Hard to say, because we don't know how much the mask will absorb, and how the masks and head move on impact. You'd actually have to put accelerometers on the mask and head, which is usually the industry's standard to measure shock.

I'd say the bullet has more than enough oomph to hurt you through impact alone (no penetration), but won't if the mask absorbs it very well. Plus, the brain is also protected through watchamacallit-fluid-stuff in your skull.
>>
>>28576602
That's a damn fine vest. The level 2 is barely noticeable under a shirt, just look like ya got a lil pooch going on.
>>
File: Mtech faceguard.jpg (150 KB, 350x350) Image search: [iqdb] [SauceNao] [Google]
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>>28586867
This is like 2010 to 2012 OIF. A lot of the senior line platoon soldiers in my old troop got a whole bunch of them to fuck around with as truck gunners. Couldn't actually use them too often because of how hot and heavy the first gen of MTEK faceguards were. They ended using them as sweetass batting cage helmets with their batting machine though.
>>
>>28575741
Come on, anon.
Why the hell would you buy a face mask if you're not going to put a skull on it?
Thread replies: 256
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