Kinetic energy is not a valid measure of how "powerful"

>>33098093
Interdasting. So when you get your head shattered by a bullet, and your brain is smeared on the wall, is the blood loss that kills you. Well there you go. Learn something new every day.

A bat being swung by a pro batter is more dangerous than a bat swung by a child. A man running at full speed is more dangerous than a woman running at full speed.

A bullet with more kinetic energy is more powerful than a bullet with less energy.

your last attempt at this thread was a failure and this thread will be too.

you need to kill yourself at your earliest convenience. not because you're wrong, but becuase you can't seem to remember where you are.

this is the house that autism built

File: 7c3.jpg (27KB, 650x600px) Image search: [Google]

27KB, 650x600px

>>33098093
>So butt blasted that you make a new thread to escape the dozens of posts calling you out as a retard in your last thread.

>>33098167
The only shot that will kill instantly is a blow to the brain stem. Any other shot will kill by blood loss. There are even people who have survived traumatic brain injuries.
>>33098182
>A bullet with more kinetic energy is more powerful than a bullet with less energy.
"Powerful" in this sense is not defined and has no units, so it's very unscientific.
>>33098186
>>33098219
I got tired of trying to explain this particular point in the context of a larger argument, so I decided that it needed its own thread.
Also, not an argument.

>>33098093
As a physicist, let me tell you how fucking stupid you are.

Kinetic energy IS a measure of how 'powerful' a bullet is. The only energy the bullet can deliver to the target is its kinetic energy (transfer of momentum). Similarly, bullets with more kinetic energy ARE more powerful than bullets of less kinetic energy. Thing about the difference in energy between a .22lr (~250J) to 5.56 NATO (~1700J). They are both .22 caliber, the 5.56 is only 2x more massive than the .22lr, but the 5.56 carries much more energy than the .22lr and thus more destructive capability.

Comparing the energy of a bullet to a baseball or a car is a pointless and idiotic comparison as they are things that aren't even on the same scale. Bullets should be intercompared with other bullets, not with cars, people, rocketships, planets, or anything else.

>>33098261
i didnt intend to make an argument

I never engage retards. they will only bring you down to their level.

>>33098261
>The only shot that will kill instantly is a blow to the brain stem. Any other shot will kill by blood loss. There are even people who have survived traumatic brain injuries.

You know what's great for causing blood loss?

Tissue damage. You know what you need to damage tissue?

Kinetic energy.

When comparing objects as similar as one bullet and a bullet that's a tenth of an inch bigger in diameter, it absolutely makes sense to look at how much energy is behind them when evaluating how much damage they will do to a body, especially when you're dealing with a round that has twice as much as another.

>>33098093
youre wrong

It's like you don't even understand how bullets work

Protip: rupturing arteries can only happen through work being done, aka energy.

If a bullet hits some fuck and stops inside them, 100% of that energy got applied to the person. Some of it was as momentum, some of it was heat. But a lot of it is by tearing through his organs

Ergo, a higher energy bullet can and will do more damage than a low energy bullet. And if you think otherwise, maybe you should throw your bullets instead.

>>33098362
And by momentum i mean translational kinetic energy.

>>33098362

To be fair, the caveat is the assumption that the bullet embeds itself inside the target. Some ammo are notorious for over penetration.

>>33098402
"Momentum"
"Transnational Kinetic Energy"

You must be some kind of undergraduate engineering retard, aren't you?

>>33098093
kinetic energy is a measure of how "powerful" a bullet is.
Kinetic energy is not a measure of how deadly a bullet is.

your assertion that people are not killed by the amount of kinetic energy alone is correct. the key is where and how much is transferred.

>>33098313

>Claims to be a physicist
>doesn't even know what kinetic energy is
lmao
Nice job embarrassing yourself on the internet, retard.

>>33098313
sounds like you have only taken a Newtonian physics class for freshmen and thing because you have a major declared it makes you the expert. Take some fluid dynamics or some other higher level courses before making a highschool level "i'm a physicist" post. If you had you would realize KE is a major influence on this subject but not the only one. Which I believe is OPs point. Its more complicated than your community college level physics lecture on power and KE. kid.

>>33098313
>As a physicist
You are not a physicist.
>Kinetic energy IS a measure of how 'powerful' a bullet is.
Define powerful.
>he only energy the bullet can deliver to the target is its kinetic energy (transfer of momentum)
So first we were using energy. Now we're using momentum. People have argued for decades about which was a better measure for bullets. Which is it, Einstein?
>Comparing the energy of a bullet to a baseball or a car is a pointless and idiotic comparison as they are things that aren't even on the same scale.
Define scale. So now you're saying that kinetic energy as a measure of "power" breaks down outside of certain limits. But what are these limits and where do they come from.
>Bullets should be intercompared with other bullets, not with cars, people, rocketships, planets, or anything else.
Why not? Because doing proves that kinetic energy is not appropriate for measuring bullets.
>>33098335
If you don't want to give a valid argument, then leave.
>>33098361
>You know what you need to damage tissue?
>Kinetic energy.
You do need a certain amount of energy to damage tissue, but the idea that more kinetic energy means more tissue damage has no basis.
>>33098402
>And by momentum i mean translational kinetic energy.
laughingwhores.jpg
>>33098458
Define powerful. When people use that word colloquially, they mean it does more damage.

Guys I believe the point that's missing is the area upon which a bullet imparts it's energy into a target. Yes a charging fatbeast has more kinetic energy, but it has a huge surface area and won't penetrate into you. It really comes down to surface area, or more specifically pressure, which is force/area. An object with higher kinetic energy will impart more force on a given area, causing more damage.

File: 20161223_165651.jpg (3MB, 3264x1836px) Image search: [Google]

3MB, 3264x1836px

>>33098485
>claims I don't know what KE is
>doesn't even point out where the error is

Nah, you're just a cunt.

>>33098510

Actually now that I read your post, I think every single statement you made was incorrect.

>>33098537
Get the fuck off this board faggot.
You've gotten enough (you)s to sate a heard of trolls.

>>33098093
actually fucking kill yourself you artist

say 9x19mm parabellum, 7.45g and 390m/s
.5*7.45*10^-3*390^2 = 566.57 J

say baseball, 96 mph and .145 kg
.5*.145*42.47^2 = 130.77 J

really makes you think...

>>33098500
>When people use that word colloquially, they mean it does more damage.
in this context, that would be true. a bullet with more KE will do more damage. ie: it does more work, work being the change in KE

>>33098568
lol i meant autist, i guess I'm the autist now :///

>>33098491
Sometimes the only way to get a point across is to dumb things down for people.
>take fluid dynamics or 'higher level' courses
Sure thing, kiddo.
How about you compute the leading terms in the S-matrix for boson-boson scattering in ϕ^4 theory, where you can take s->infinity and t fixed. Oh? You can't? Why not? Haven't you taking quantum field theory?

>>33098562

I'm not OP, I just thought it was funny how you tried to get away with such a dumb post.
I mean, you could have just read a wikipedia page on KE and avoided like half of the mistakes you made.

>>33098600
You keep claiming he is making mistakes but you have yet to point one out.

>>33098500
>but the idea that more kinetic energy means more tissue damage has no basis.

Shoot yourself with a .38 special and a .357 magnum.

See which fucks you up more.

Just because there's not a linear relationship of joules to liters-of-blood-per-second-lost doesn't mean they're not closely related.

It certainly matters a lot more than tiny fractions of an inch in bullet size, which is what you were meming about in your other thread.

>>33098582
>guess I'm the autist now :///

Like pottery.

>>33098600
Not physicist guy,
You're a retard. Kill yourself, then apologize to your parents for wasting their time.

>>33098093
>>33098500


It's a perfectly valid way to measure what it does to a target. Your basketball analogy fails in two ways;

A) the energy of a basketball isn't comparable to even a subsonic 22.

>22@ 40 grains (2.5 grams) and moving at 1065fps (324m/s) yields 131 joules
>Basketball@ 623.7 grams moving at 8m/s (avg free throw shot velocity) yields 19 joules
> Result: your off by a factor of almost 7

B)A basketball has as much larger surface area that the average bullet, and as such it will require a massively larger amount of energy to penetrate flesh, if you threw a basketball with a 22 cal rod sticking out of it, and it hit you dead on, it would do just about as much damage as a 22 from a pellet gun with similar energy to a basketball. Think of it as trying to poke through fabric with a small stick vs a large stick, if you wack them with a hammer and impart the same amount of energy to them, the small stick will go through, whereas the large stick won't since the energy is dissipated over a larger surface area.

>>33098658
Not only this, but getting hit with a basketball turns pretty much all of it's energy into heat and translational kinetic energy, whereas bullets do not.

If i push you vs if i stab you with the same energy, the action is extremely different and imparts it's energy differently, making basketballs a very poor comparison to bullets

>>33098611

Alright, let's open wikipedia and do exactly what I just said, since you clearly are completely incapable of doing this work yourself.

>Kinetic energy IS a measure of how 'powerful' a bullet is. The only energy the bullet can deliver to the target is its kinetic energy (transfer of momentum).

https://en.wikipedia.org/wiki/Kinetic_energy

>>It (KE) is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

KE is just the amount of work done on a body.
It is not directly related to power.
Further, objects do not "transfer energy" in terms of KE.
Assuming a rigid body collision, with no thermal energy loss, (both of which are untrue in bullet impacts, but whatever), an object loses kinetic energy when another object does work on it.
It's not a "transfer", and no physicist would call it that.

>>33098649

You must be very angry to make such a post.

>>33098500
Not the guy, but if you knew anything about physics you would know that in an inelastic collision ( such as a bullet entering the body, with both the body and bullet becoming deformed and possibly the bullet getting stuck in the body) energy is not conserved. You would have to do an energy/momentum conversion.

>>33098707

Gee, it's almost like comparing KE between two different objects isn't always a good indicator of how deadly they are.

>b-but it's fine for bullets!
A lead 45-70 and an AP 5.56 both hit you very differently too.

>>33098808

>tells someone else he doesn't understand physics
>doesn't know the difference between an elastic and inelastic collision
fucking kek
The rest of your post was a shitshow too.
I'm not even the guy you replied to.

>>33098093
More holes means more bleeding. Smaller calibers are therefore better because they offer greater capacity.

>>33098508
That's the exact same thought I was having. You could even do some kind of formula.

Something like kinetic energy divided by bullet cross section in mm. This gives you units of energy per square mm, which you can then call stopping power or whatever else you want to term it.

>>33098850
Sectional density killed JFK

>>33098753
Now you're the one who's an idiot. Object do not lose energy when work is done on them, they gain it.

>>33098817
If we assume that the bullet becomes lodged in the person, the results will be pretty similar. Otherwise, you just have to take into account the exit kinetic energy and the result is the same. Faggot.

>>33098753
Using the subjective term "powerful" is suddenly misuse of KE.
>Sure thing

Notice how it was in quotes (again)? Because it is a colloquial term, not the physical measure power ([energy]/[time]).

For you exmaple of lossless collisions, bodies must conserve energy and momentum. These conservation laws can be thought of as the transfer of momentum/energy between objects. So yes, it is transfer.

File: lolgif3.1.gif (1MB, 150x113px) Image search: [Google]

1MB, 150x113px

>>33098882

>>>>>>>>>>>>Object do not lose energy when work is done on them, they gain it.

HAHAHAHAHAHAHAHAHAHAHA
FUCKING
W O W
O W O
W O W

>>33098841
How is a bullet colliding with a body not inelastic?

>>33098932

Go look up the definition and find out.

>>33098910
>not understanding what work is
I almost feel bad for you

File: IMAG0018.jpg (346KB, 2560x3136px) Image search: [Google]

346KB, 2560x3136px

guys physicist here.

Suppose a .25 inch^2 bullet travelling at 2500 forces/sec impacts a dude. Will it create enough stopping power to kill him?

Well according to my calculations it will.

(2500 forces/sec)(.25 inches^2)= 156.25 force inch squared per second. This gives us our pressure gradient with respect to the area.

Now we need to know how much this penetrates. First we need to find the partial derivative of this function with respect to inches. Take the derivative with respect to inches giving us:

d/d(inches) = 156.25 inches^2 ->
*using power rule
2(156.25)inches (2-1)=312.5 force inches per second. Say the impulse is a 4 force for .1 seconds

(312.5 force inches/ second)(4 forces*0.1 seconds)
canceling out the seconds leaves us with 125 inches of penetration power.

>>33098093
>blood loss
>not critical organ failure

A shit attempt at trolling, at best

>>33098658
>>33098850
>>33098500
Think of it like this, look at the damage you do to your target, (assuming you don't hit something vital), as the change of energy from when the bullet enters the body vs. when the bullet exits the body. Although this doesn't hold true for massive deviations in the projectile, (think hitting someone being hit with a basketball going 40mph, which is what you would need to match a subsonic 22, most of the damage will be crushing based, rather than piercing as with a bullet, or hollowpoints vs fmj), it does allow you to make comparisons for similar projectile sizes and types.

Keep in mind, this only looks at things from an energy prospective, I'm neglecting the losses due to tissue compression/heat/etc. for simplicity.

Think of it this way if you shot a 9mm, .40 and .45 cal bullet that all had the same weight and were shot at the same speed, you could reason that they would all have the same amount of energy, but your intuition would tell you that the 9mm would penetrate further than the .40 which would penetrate further than the .45, This is because due to the larger projectile diameter, it has to push deal with pushing more flesh out of the way which requires more energy. You can think of this as the bulled loosing a specific amount of energy for each inch traveled. The rate of this energy loss is going to be faster for larger rounds, but at the same time, it's harder to propel them at high speeds, so for similar rounds stopping power is about the same.

Keep in mind this analogy may not hold for other factors such as target density/bullet material/type, I would assume that the modeling of the target as a mostly solid object would be ok since the speed of the bullet is high enough that the elasticity of the medium wouldn't matter much.

>>33098973
You're not a physicist.
And posting an image of some bullshit math does not prove you are a physicist.

This guy >>33098510
is likely a physicist because I cannot identify what any of that shit even is, but it looks physics-y.

>>33098961
I don't think im any of those people, but
bullet collisions are, in fact, inelastic. Because a perfectly elastic collision would result in the bullet rebounding off of your skin

>>33098841
...but he's right. A bullet entering a human body and either exiting at a reduced velocity or becoming embedded in the body is an inelastic collision, meaning kinetic energy is not conserved. A momentum evaluation is correct, even though it's mostly meaningless because the mass of the body is orders of magnitude greater than the mass of the bullet, so the post-collision velocity measurement of the body is negligible.

Kinetic energy isn't the perfect means to evaluate the damage potential of a bullet to a human, but it's the easiest to understand. Energy is defined as the capacity to do work. Work is needed to deform or destroy human tissue & bone, so up to a point, so the more work a bullet can do, the more likely it is to be able to do the necessary amount of damage to stop a target.

Either way, this is an asinine discussion, because shot placement is so much more important. Would you rather be shot in the finger by a 50BMG or shot between the eyes by a 22lr?

>>33098973
You've failed to account for the rotational terms, which are significant in any consideration of a bullet fired from a rifled barrel.

Presuming a 1:9 twist rate gives your hypothetical bullet a rotational velocidensity of ~10% of its forward motion, reducing its effective penetration due to the increased friction

>>33098969
https://en.wikipedia.org/wiki/Kinetic_energy
>>the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body in decelerating from its current speed to a state of rest.

>>33098975
https://www.youtube.com/watch?v=wXwPtP-KDNk

>>33098993
autism
>>33099003
he gets it

>>33098961
I did. The bullet doesn't "bounce" off the body. It embeds itself in the body, and deformation occurs as well as other non-conservative forces such as heat transfer from friction.

An elastic collision, on the other hand, would be when two objects bounce off each other with no deformation or imbedding.

>>33098998
*with no deformation or restitution of either object.

The guy you're replying to is a fucking 1.7gpa Civil Engineering freshman, don't waste your time.

>>33099003
>velocidensity
lol, can't stop laughing. I'm going to steal this one from you when fucking with /sci.

>>33098993
>forces/sec

What tiped you off?

>>33099008
If they're treating you in a hospital for gunshot wounds, someone clearly missed the important bits.

>>33098999
Would delta-v be a good indicator? Basically with the idea that the more energy lost to deformation (the bullet expanding and deforming as well as the flesh), the higher the difference in initial velocity vs. Final velocity?

>>33098093
Oh, what's that? hydrostatic shock actually real? whaaaaaaa


https://arxiv.org/ftp/arxiv/papers/0803/0803.3051.pdf

>>33099005
Yeah, the body iS DOING WORK ON ANOTHER OBJECT, AND THEREFORE HAS NEGATIVE WORK DONE ON IT

NEGATIVE FUCKING WORK

IF I BREAK YOUR FUCKING HEAD IN, IM DOING WORK ON YOUR FACE AND THEREFORE AM GIVING IT ENERGY

BUT MY FISTS ARE LOSING ENERGY BECAUSE THEY ARE DOING WORK YOU ABSOLUTE FUCKING MORON

Work being done on an object gives it energy.

An object doing work LOSES energy. You pseudoscience cocksuckingpiece of shit.

>>33099061
Yes, it's generally close enough for off the cuff comparisons between similar rounds.
>>33098985

>>33099081
Work is always positive, you can't have negative work. The vector can change, but it's always positive.

"negative work" is represented as positive work along the opposite vector.

>>33099003
We can formulate an unconstrained nonlinear optimization problem to determine the ideal caliber and muzzle energy by assigning weighted cost functions to performance metrics, approximations for which can be developed by fitting functions to the available data. Penalty or barrier parameters can be added to limit the search space to feasible solutions without imposing hard bounds.

Because the two quantities being solved for are not independent and the functions are not strictly convex, we are likely to find multiple solutions and may need to explore other methods, as such the proposed funding level for this project is for two students full time, 10 hours/week for the PI, and necessary equipment costs.

>>33099081
Vectors have both magnitude and direction and can be considered as either positive or negative as is convenient. You'll run into pistons and shit 'doing negative work' all the time once you hit those 2000 level classes my man.

>>33099061
it could be if you knew how fast a bullet was going after it passed through a body since the change in velocity is directly related to the change in kinetic energy, which is equal to work done.

>>33099042
You do realize the unit force/time is actually a real measure? It is called force onset rate and is used in a variety of engineering applications.

>>33099140
But you'd need to know how much of that energy transfer was elastic vs inelastic.

>>33099148
Forces isn't a recognized unit for force, it isn't like torques.

>>33099061
I mean, you can take the initial KE of the bullet just before impact, and then the KE of the bullet after over-penetration to get a measure of the work done on the body using the work-energy theorem, but there are so many shot-to-shot variations that I don't think it would be any more informative than making your judgment based on initial KE. Work done on the target will vary greatly depending on where & what you hit; a bullet that hits a rib on the way in & out, tearing up a lung in between, is performing much more work (and therefore, damage) on a target than an identical one that passes above the collarbone and travels through 3" of soft flesh.

Again, it's a fairly asinine argument because shot placement is exponentially more important. I understand that bullet selection is an easy variable to control here, and so one would like to optimize it, but it's a comparatively minor variable.

Training is key.

>>33099148
If you're not using N/s you can stand in the trash where you belong.

>>33099168
Looks to me like he just made a typo as in the same line, and subsequent lines, he calls it force.

>>33099068
>hydrostatic shock
Hydro means water. Statis means still. If hydrostatic shock meant anything, it would mean "shock caused by still water." It's a pseudoscientific term.

>>33099133
Dumb negroid.

>>33099191
I'm not literally an engineer or anything.

>>33099179
Slug feet per second cubed or get the fuck out eurocuck

>>33099155
and a couple other things that are nearly impossible to determine outside of a perfectly controlled environment. which is why we just use KE and came to the realization that shot placement is most important.

>>33099220
Take your Stones/daycycles and gtfo, Britfag!

>>33099233
Or why they do ballistic gel tests.

And why some wierdos shot some goats and timed their time to collapse.

>>33099148
>defending this post
>force inch squared per second
>partial derivative of this function with respect to inches
>d/d(inches) = 156.25 inches^2 ->
*using power rule
2(156.25)inches (2-1)=312.5 force inches per second

arguing about forces per second in context of this post

autism at its finest

>>33099186
u dint even read the link did u, u little faggot

>>33099253
Lots of people learn the specific application of the power rule before generalizing to the chain rule, it isn't really a mistake.

What's the point when pistol rounds are universally shit at killing people anyway? Comparing cartridge A to Cartridge B is like trying to decide which turd stinks less. It all boils down to personal preference and that's perfectly OK. It's useless busting out charts and mathematical equations for something that doesn't matter in actual flesh and blood situations where these rounds perform. Use what you like.

>>33098093
So what you're telling me is that there's no difference shooting someone in the head from 300 meters with a .22 Short and a .22 Hornet? Neat.

>>33099299
>partial derivative of this function with respect to inches


how autistic are you. Most ones I know are good at math. But you, are a special kid. Not realizing the joke/troll. Taking a partial derivative with respect to inches. I'm assuming you don't realize how stupid this sounds and are pretending to be able to understand the discussion as if it was serious when it clearly was a troll.

>>33099186
>Statis = static

https://www.youtube.com/watch?v=bFtcLJVN8yg

>>33098182
Its not so cut and dry though anon. For example if we got bumped in the parking lot by a vehicle weighing 6000 pounds at 5 mph, that hit would equal 5013 pounds of kinetic energy. I would rather take a bump from a pickup truck at 5 miles per hour than get shot with a .22LR.

To step it up a bit, if we know took a bump from a piece of heavy equipment weighting 20000 pounds at 5 MPH that would equal 16713 foot pounds of energy. In this instance I would still perfer to be bumped by a piece of heavy equipment than to be shot with a .22LR

Ready for the next one?

If we worked at Cape Canaveral and got bumped by the largest vehicle on earth, the space ship mover. 4 million pounds at an unbelievable 5 MPH would equal 3,342,582 foot pounds of kinetic energy. I think that I would still perfer getting hit with 3 and one third million pounds of kinetic energy than getting hit with 135 pounds of energy from a .22LR

What are your thoughts anon?

>>33099307
>Fuddlore

If you don't think .357 (out of a proper 4" barrel) is deadlier than .38 special, you're just a herp derp

>>33099253
I'm not defending his post other than the fact that force/sec is a real unit.

The rest of what he is doing is shenanigans, but you shouldn't be so surprised by doing a d/d(inches).

Many times, when I have done a reverse integration (read as integration by parts shortcut), it has been with respect to numbers or the like. For instance do turn an integral into a Gaussian integral I could do, I needed to reverse a d/d1, and in another instance a d/dπ.

>>33098440
hey dont lump me in with that fag

>>33099329
Well it's not like he needs the gradient, all the other terms are zero. Estimating the impulse at 4 forces might be somewhat low, but 0.1 second is too high and probably about cancels. and it's all an approximation anyway. As I said before, even neglecting the rotational components only puts him off by 10%

>>33099378
That energy isn't transferring into your body efficiently. Compare to that truck hitting you at 5 mph, but your back is to a wall.

Also, use ft-lbs; pounds is not a measurement of energy, but of mass

>>33098510
Is that a fucking particle accelerator?

>>33099380
magnum pistol calibers are slightly more likely to kill but overall, hes right. most pistol calibers are pretty shit for killing a human sized target, with only slight variances in how shit they are.

>>33099395
FORCE ISNT A UNIT ITS A VECTOR QUANTITY NEWTONS ARE A UNIT OF FORCE POUNDS ARE A UNIT OF FORCE SLUG FEET PER SECOND SQUARED ARE A UNIT OF FORCE

>>33099395
No it isn't. I've never heard of it, and Wolfram alpha doesn't recognize it.

It's probably some generic placeholder for use in math equations, but a "force" is not a real unit. A "force" is a physical quanity.

>>33099378
>If we worked at Cape Canaveral and got bumped by the largest vehicle on earth, the space ship mover. 4 million pounds at an unbelievable 5 MPH would equal 3,342,582 foot pounds of kinetic energy. I think that I would still perfer getting hit with 3 and one third million pounds of kinetic energy than getting hit with 135 pounds of energy from a .22LR

Except that in all those situations all you're experiencing is your own body accelerating to 5mph. Even if you're hit by a an infinitely massive wall moving at 5mph, the energy transfer will only be however much it takes to accelerate you to 5mph, which is about 200 Joules.

This is still more than the .22LR of course, but not much, and is nice and spread out over your body.

>>33099423
Probably an electric turbine generator.

>>33099431
All the test data I've seen contradicts this.

>>33099437
>Foot-Pounds

>>33098093

Force is a scientifically measurable quantity and I think it has a lot to do with killing someone. If I shot you with a .50 cal , do you really think it'll be the blood loss that'll kill you?

>>33099474
Torque

Perhaps [(KE initial - KE after exit)/surface area ] is a better measurement. So basically amount of energy that performs work on the flesh of the target is a better measurement. Subtracting kinetic energy of the movement of the person being shot would be even better but not very practical. A bullet does damage by piercing, not blunt force trauma.

Hollow point bullets dump more energy because they don't over penetrate as much, and more work is performed destroying the tissue of the target.

>>33099380
Shot placement is God, everything else is retarded bullshit for girls to bicker over. Your .357 won't do much of shit if it doesn't hit something vital.

Also,
>Carrying a revolver

Get the fuck out of here, YankeeMasturbator

>>33099465
>b-b-b-ut muh Data!
Then start posting the shit you've seen, because for all we know you could just be some moron spouting bullshit.

>>33099484
Torque is an application of force, yes.

Pounds is a unit of mass. You can google this shit in like 2 seconds.

>>33099437
I think the guy is just trying to use "force" as a replacement for units to make his calculation independent of the unit system your using, like calling energy (mass*length^2)/sec^2, it's just in fundamental units using "Force" as a replacement for (mass*length)/sec^2

>>33099465
>All the test data I've seen contradicts this.
feel free to post the data

>>33099488
KE after exit is different on any shot against any target and can only be measured if Trayvon II happens to be standing in front of a chrono when you plug him.

>>33099490
Yeah, but a .357 to the lung is going to do a lot more damage than a .38 to the lung.

unless you hit the core function region of the brain, or the heart, it typically matters.

There is also the felt impulse, which dictates a round's ability to incapacitate.

>>33099501
lbf and lbm are different units and lbf is assumed when not otherwise specified.

>>33099500
http://guninstructor.net/Strasborg_Tests.pdf

Or google any gel test.

>>33099522
Bro if you're shot in the lung you're fucked either way it doesn't matter what caliber you got hit with.

>>33099412
pounds force is a thing. i didnt bother to check if his math is correct though.

>>33099510
Yeah, so it would need to be standardized and simplified for purposes of comparison. How about force after 12" of standardized ballistic gel? You can't distill power to a single number and of course where someone is hit matters a lot more than the bullet or gun.

>>33099524
http://letmegooglethat.com/?q=foot-pound

>>33099490
>Shot placement is God

A lot of people say this but don't back it up by carrying a .22 short.

Everything is compromise.

File: totally_legit_math.jpg (347KB, 1000x563px) Image search: [Google]

347KB, 1000x563px

>>33099395
I found an old piece of work in which I had to do do a d/dπ.
It is a neat trick, for sure.

>>33099454
Yes, it is. Wolfram "Newtons/second" and you shall see. Newtons is a unit of force, seconds is a unit of time. Newtons/second would be force onset.

>>33099557
>The foot-pound force (symbol: ft·lbf)[1] is a unit of work or energy in the Engineering and Gravitational Systems in United States customary and imperial units of measure. It is the energy transferred upon applying a force of one pound-force (lbf) through a linear displacement of one foot. The corresponding SI unit is the joule.

Shit did you just counter trollphysics me

>>33099540
Yes it does, a lung hit isn't always lethal.

And it's not about killing someone, it's about incapacitating them. Else they'll probably shoot you in the lung.

>>33099575
The best way to incapacitate is to kill.

>>33099570
You are confusing the quantity force with the 'unit' force which isn't a thing. You can refer to a quantity as Force/Time or to a value in Newtons/Second but Force/Second and Newtons/Time are meaningless. Go be a mathematician somewhere else, real people are talking.

>>33099574
Ah, I see. My mistake, you left out a "force" so it looked like you said "Pounds are a unit of force"
instead of "Force Pounds are a unit of force"

I blame the english and they're retarded imperical system.

>>33099534
you realize this basically says that projectile construction >>>> caliber, right? which is also what nearly every gel test tells us.

>>33099559
that would be a valid argument if .22 short penetrated deep enough to actually hit vital organs reliably.

>>33099605
>WRONG

That is the most inefficient way to incapacitate.

>>33099614
You're extra wrong because ft-lbf are units of energy and not force.

>>33099540
>As Platt climbed out of the passenger side car window, one of Dove's 9 mm rounds hit his right upper arm and went on to penetrate his chest, stopping an inch away from his heart. The autopsy found Platt’s right lung had collapsed and his chest cavity contained 1.3 liters of blood, suggesting damage to the main blood vessels of the right lung.

Platt went on to kill two FBI agents and wound 5 others before succumbing to his wounds, which included the described lung shot and 11 other shots, mostly from 9mm and .38 special handguns.

>>33099610
Have you heard the phrase "intellectually disabled" often?
Newtons/second is a valid unit. Nothing more, nothing less. No confusing terms, no mathematician things, just stating a fact. You are falling for some real troll 'physics', my friend.

>>33099626
I am aware, we are talking about KE

I am a bit unfamiliar with imperical units, though, I will admit.

>>33099639
I just said that newtons/second is valid you illiterate goddamn baboon. 'forces'/second is not because 'forces' isn't a fucking unit.

>>33099510
Sure, but assuming you only hit flesh, just treat it like a really intense drag force, CdD(v^2)A, you would need to determine the Cd (Drag coefficient) experimentally, and it would be apt to change at higher/lower velocities, you would also need to develop a value for the average density of a human, but it would allow you to get a rough approximation of the retarding force on the bullet, after that it's just a matter of integrating the thing to find out the delta V.

>>33099653
I don't see why you are getting upset. I never said forces; the troll who wrote forces/second looked like a typo for force/second, to which you could replace 'force' with a valid unit of force, and have a real measure. I am in no way agreeing with any of his chicanery, just pointing out that force/time is a real unit (like N/s).

>>33098093
I've always argued that transfer of energy from round to target is more important than kinetic energy.

the classic .45 stoppan powuh round doesn't overpenetrateand dumps most of its energy quickly.

rounds with more penetration lose energy to momentum rather than transfering it to the target.

>>33099639
>travelling at 2500 forces/sec impacts a dude
>travelling at
>velocity in a unit of forces/sec

you pedantic autismo bot. go away

>>33099709
see >>33099695

>>33099702
>rounds with more penetration lose energy to momentum rather than transfering it to the target.

Do you hear yourself speak?

>>33099617
>reliably.

How reliable do you want to be, is the question. Any practical handgun cartridge has some failure rate when it comes to incapacitating. I've met someone who took a .40 S&W to the back of the head and survived. Meanwhile people die to .22LR all the time.

Shot placement is important, but lady luck gets the final say, and being able to deal with shit luck is why I personally prefer calibers that allow higher capacities.

>>33099662
Or you could just shoot a target of known composition that approximates the properties of flesh and of sufficient depth that the projectile comes to a stop. You can then directly measure the maximum penetration achieved and compare different oh wait fuck

No worthwhile conclusion can be made from trying to reproduce a representative average human torso and measuring overpenetration because the variance will be huge in experimentation and even more huge in practice.

>>33099695
Units are different from the quantities the measure. Time as a quantity or length as a quantity are conceptually distinct from a value of seconds or a value of meters.

>>33099745
Please reread the post you are responding to.
I, in no way, support his "forces/second". I am just sharing a bit of trivia that [force]/[time] is a valid measure.
Nothing more, nothing less.

>>33099724
theres a difference between "somebody could conceivably survive taking this round to a vital organ" and "this round will almost certainly not penetrate deep enough to reach the vital organ in the first place".

>>33099767
Congratulations, any other staggering insights from middle school you'd like to drop on us today professor?

>>33098093
>cannot be mathematically quantified

maybe not for a retarded autist like you

>>33099783
You don't have to be rude. If you don't like a bit of trivia then you don't need to respond or read it. Just close your eyes or look away from the computer.

>>33099207
You're right, you're not. Energy is a scalar, not a vector.

>>33099378
You are comparing apples to oranges. The comparison should be between apples and apples. A .50 BMG is more powerful than a .22 LR.

>>33099709
>>33099799
>>33099799
this is you
>dude you are being an asshole
>well acshually an asshole would smell bad and I shower and don't smell, therefore don't resemble the smell of an asshole
>well acshually my body type resembles nothing close to an asshole. I'm long and have 4 extremities on my body.

>being an autistic pedant.

>>33099851
>Semantics