9mm BTFO

Retardation.

>>33302117
it's not so much the weight of the impact as it is the hole it pokes in the person which lets the blood out. let somebody poke a few 9mm holes in your chest area and see how much you laugh about how that felt like 10 pounds dropped from less than an inch.

sage shitty b8 threads

>>33302117

They forgot to add that the 10 pound weight would have a 9mm cross section.

>>33302164
And that 10 pound weight would be travelling 1100+ feet per second.

>>33302174

No, no, a 9x19 bullet doesn't weigh ten pounds.

>inches
>pounds

RRRRRRRRRRRREEEEEEEEEEEEEEEEEEE

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>>33302178
gas yourself

What if I dropped a 10 lb weight, with a diameter of 9mm? Maybe a pole, or like a ball with a protrusion?

>>33302215
Then youd have the equivalent of a 9millimemer.

>>33302117
Who cares, a well placed shot is going to kill you

That's all that matters

>>33302164
This, that's pretty bad still. Still not representative of what a bullet would actually do, just a raw measure of energy on impact.
>>33302174
This is fucking retarded, you just turned 9mm into a anti-tank gun.

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>>33302174

>>33302117
>itt: /k/ displays its lack of knowledge in highschool level physics

>>33302117
Momentum and energy are different things. Velocity has a bigger impact than mass when talking about energy. Maybe this guy is talking about energy and just used the unscientific word "impact", I'm not in a position to do napkin math right now so someone else will need to

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>>33302204
>Metric is superior.
>hasn't gone to the moon.
K E K

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>9mm fags on damage control.

>>33302317
I would assume hes just using momentum to for dramatic effect and to scare 9mmfags who dont understand the difference between momentum and KE or how bullets kill a person.

I dont feel like calculating the velocity to confirm though.

>>33302344
>>Metric is superior.
>>hasn't gone to the moon.
It did go to the moon, Von Braun team used metric system.

>>33302174
>you see, when you shoot someone with a shotgun they go flying across the room
- the post

>>33302317
This is easy stuff, you can do it in your head. Just truncate and write in scientific notation and fractions, much easier.

10 lbs is about 4.5 kg, 0.72" is about 0.018 m
E = mgh = (4.5kg)(9.8m/s^2)(0.018m) ~ 0.8 J
9x19mm 115gr projectile, standard load, E=~560 J
So it is definitely not an energy comparison.

Momentum perhaps?
p = mv = m(sqrt(2gh)) = (4.5kg) sqrt(2(9.8m/s^2)(0.018m)) ~ 2.7 kg m/s
9x19mm 115gr projectile, traveling at 390 m/s p=2.9 kg m/s

Looks like it he was comparing momentum.

>>33302174
9.8m/s actually you fucking fag.

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>>33302204
Get out of here communist...

>>33302422
It wouldnt be traveling at that speed, it would accelerate at 9.8m/s^2 for .72 inches. The final velocity would be like 3.9ft/s

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>9mm
https://youtu.be/bHFz04f9Ikg

>>33302451
Check your math. It is ~1.9 ft/s.

People do realize that the amount of momentum conferred into the bullet is equal and opposite to the momentum conferred into the person holding the gun firing said bullet right?

Like, if you want a shotgun to blow your opponent across the room, you need to also be blown across the room. Conservation of momentum and energy yo.

Regardless, the momentum of an item hitting you isn't the end-all-be-all, unless that item has perfect elasticity and you are impenetrable so the only form of energy it can direct into you is via that collision.

Thankfully humans aren't impenetrable, bullets do a whole hell of a lot more than bounce off us, and we have all that blood and important function of various vital organs keeping us alive to be worried about.

Bullets of all calibers can kill you, they don't need to knock you off your feet to do so either. Find me a kid with the smallest caliber and lowest energy derringer fired plastic round lodged into the reticular formation in his spinal cord and I will show you a kid that is going to die from one bullet regardless of surgical intervention.

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>>33302492
>Like, if you want a shotgun to blow your opponent across the room, you need to also be blown across the room.

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>>33302511

>>33302480
Youre right. Forgot to take the root.

>>33302393

Nice. I always forget that little time saver of K = mgh.

>>33302264
Shhh, this is /K/, not real life

>>33302368
Tannerite?

>>33302372
How'd that first mars landing go?

>>33302840
No. That's just how powerful 9mm RIP rounds are.

Could somebody make tho same comparison to an axe head hitting someone? Or an arrow? I'm sure there's a boatload of things you could make this silly comparison to.

>>33302915
Works best with bullets because they have a large difference between mass and velocity

>>33302832
>/K/

>>33302117
The pushback is minimal
It'll still fuck your entire life up though senpai

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>>33302492
>if you want a shotgun to blow a person across the room then you need to be blown across the room, too

well let's say that the shot has just enough energy to do that. wouldn't you being blown back use half the energy that the bad guy would get blown back with? is that the reason why limp writing causes extraction issues or whatever?

>>33303146
sure, whatever you say kohai

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>>33303354

Conservation of momentum is the reason why so many things in hollywood shooters don't make any sense.

In other words ∆u1(guy you shoot) has to equal ∆u2 (your ass)

u=m*v so the things you can change initially are mass (if you are super heavy and he is super light then he will move more than you do), or at time of shot being fired you can change the distance over which the acceleration (represented by the m∆v = ma, which is just Force), occurs. You can waylay that potentially by intelligently using your arms and legs as a compressible piston of sorts, but ultimately if you want a shot to pick a guy up and move him there is a very small chance it won't do the same thing to you without doing calculations that ultimately defeat the purpose of designing ammo to do such a thing.

OP is being a faggot and not giving any context to the statement. I wrote a 10 page paper about the wounding effects of common handgun rounds and incapacitation in college and I used this statement as a quote but there's more to this entire article were this statement is found.
The depiction of a 10 lb. weight being dropped over someone's chest isn't about the wounding capability of 9mm but of the physical stopping power of the round
I.E. >stoppin' powah, meaning physically knocking your ass on the ground because of the force of the projectile, does not exist with 9mm, .40, or .45 or other handgun rounds (.50 DE or a revolver in .500 are debatable because i didn't research their physical projected force)
There are two reasons people fall over that are described in the paper that is being referenced. 1# People watch pop culture movies where everyone falls over after being shot once and get flung back far from handguns so psychologically people are already trained and conditioned to fall to the ground after being shot (even with lack of actual physical incapacitation causing them to lose control of motor function) and #2 is the obvious physical inapacitation caused by a bullet hitting the CNS (spinal cord or brain) or causing enough blood loss to transfer oxygen to the brain.
>tl;dr handgun rounds push you backwards as much as a 10 lb. weight hitting your chest from an inch away

>>33303911
>(.50 DE or a revolver in .500 are debatable because i didn't research their physical projected force)

They're not debatable at all. In order to knock down the victim it would have to be powerful enough to also knock down the shooter.

How do you figure out how far a bullet would move a 1-lb object? I just want a rough idea.

>>33304347
>shoot it
>learn calculus

choose both

>>33302422
You're even more retarded than OP, good job!

>>33302511
will this break your gun if you shoot it?

>>33304510
they dont call it a boomstick for nuttin

>>33302897
Cardboard is well known to cause the most expansion

>>33304510
More likely there wouldn't be enough powder to accelerate all that shot properly so the wad would get stuck halfway down the barrel.

>>https://m.youtube.com/watch?v=puzuqS1D2Lc

>>33304347
By taking an introductory physics course, specifically in classical mechanics.

Basically you take the speed and mass of the bullet and the mass of the object being hit and you do some fun energy transfer calculations which I don't remember the particulars of because I'm on the can and haven't done classical mechanics problems for about a year.

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>>33302117
>9mm, in this case i'll use 124 grain FMJ (8.04 grams) going at 360 m/s (1,200 ft/s), with 521 J of energy
>equal to a 10lb weight dropped from .72 inches, which would be 0.81 joules
>To actually achieve this force, you would have to drop it from approximately 11.74 meters or 38.52 ft. Basically dropping a fair sized brick or a computer monitor of the side of a four story building.

Who the fuck wrote that.

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>>33302117
Physicist here

>TL:DR Hollywood lies to you.

It's referring to the total kinetic energy. He's basically just saying that shooting someone doesn't instantly knock them over, and it doesn't cause them to go flying into walls or off of buildings like in the movies.

The reason bullets penetrate and the weight does not is twofold. First there's the obvious surface area issue. Bullets are (at least somewhat) pointy, and a weight is not. But a knife strapped to the weight dropped on you won't penetrate much either. Sure you'll get poked if it's a sharp knife, but even a scalpel isn't going to go clean through you. That ties into factor two. Time. Bullets move fast. Even handgun shots move fucking fast. A slow moving object will deliver its energy over a long time period, while something moving at the speed of a bullet delivers all of its energy in a tiny tiny fraction of a second.

If you graph the amount of energy being transferred with respect to time, the area under that line will be the same for both the weight and the bullet, but the bullet's line will be a short sharp spike, while the weight is a much more gradual bump.

It's that sharp spike in power that gives you penetration. Your skin and absorb and deflect enormous amounts of energy, and that's before your skeleton comes into play, but if you exceed the thresholds of your skin, even for an instant, it will fail.

I'm oversimplifying greatly here, but you should get the idea. There's all sorts of fun shit with the elasticity of the collisions, the points/surface areas involved, the angles, and different types of materials, material strengths, etc to consider, but the TL;DR is that fast moving things deliver their power more quickly in an impact, which means its easier to exceed material tolerances. In this case that means that a bullet is far more dangerous than dropping a brick on your foot from chest height, despite the brick having faaaaarr more kinetic energy.

>>33303385
Are you implying you'd be fine if I shot you with a 9mm and got away scot free?