How much force would it take to blast bone chunks out of...

[Davey]

The past couple days I've been working on a satirical crossover fanfic, and I've hit a bit of a snag, not having the best grasp of physics or anatomy. I'd really appreciate some help.

I'll try to outline the scenario as best as I can.

In one of the parts of the sci-fi I'm working on, there's a part where one of the robots punches a punk in the arm hard enough to blast chunks of bone, flesh and scraps of skin out of the other side. The punk is assumed to be human, caucasian, aged nineteen, a city dweller (not the toughest kind of person), and with an average to above average build; bottom line, your stereotypical brainless high school jock who's barely squeaked through most of his classes, flunked a couple more and isn't too bright, but is pretty good at intimidating and beating up people smaller than him. The robot is assumed to be from a Science-Fantasy universe where the line between technology and magic gets kinda blurry, so it'd be incredibly powerful. 'How powerful' is the thing I've been wondering about, though. The robot is assumed to be anthropomorphic, about six feet when standing at full height.

The robot 'punches' the jock's arm with a hook punch, hitting the upper arm between the elbow and the shoulder, and then stops almost immediately after contacting the bone, so the punch does not follow through like a normal punch might. The jock's upper arm bone breaks into splinters, the splinters burst out the other side, opposite from the punch with so much force it opens a big wound from hydrostatic pressure, and embed themselves approximately one inch deep into the meat of his torso.

The big question I have is: how fast and how much force would the robot need to smack this jock with in order to cause a wound like that?

Also, how strong would the robot's knuckles and/or limbs need to be to allow it to do something like that, as well as crack apart one-square foot cast iron ingots without deforming? How much force would it take to smash a solid brick of cast iron a foot high, a foot wide, and a foot tall, sitting on solid ground?

I'd appreciate any help I can get. If the numbers get too high or too unreasonable, I'd like to know before I continue. Thank you very much.

[Darth Ruinus]

After doing some calculations, I have come up wit this.

"The robot punched the jock with enough force to break the jock's upper arm bone breaks into splinters, the splinters burst out the other side, opposite from the punch with so much force it opens a big wound from hydrostatic pressure, and embed themselves approximately one inch deep into the meat of his torso. Even though the punch didnt fully connect."

As how strong the thing has to be? Well, after lots of calcs, I got this

"The robot was made out of materials so strong, that it could crack apart one-square foot cast iron ingots without deforming."

Sorry, for the joke post, but damn that sounds like a pretty crazy robot. Is it a military model or a civilian one?

[Davey]

Military, of course. No properly corrupt government in the near future is going to let their citizens play with guns, let alone avenging killer robots of devastatingly deathly deadly doom.

It's a satire, but at the same time I'd just like to know, out of curiousity, and if the numbers get too high, then I'd also like to know before I go any further; I want it to be portrayed science fantasy, not omfgwtfpwn-technowankery. If it crosses into omfgwtfpwn-technowankery, and if I could see the numbers now, then I can scrap it and take on a milder, fresher idea right away, and not after I've spent effort on something that's just going to fall victim to the little button marked DEL. Of course, chances are I'll just punch up the 'FIND' function and tone it down, but I'd like to know where this is going so I can write things right the first time, instead of having to scramble around with a highlighter and pen looking for the problems and wasting time I could have spent working on finishing the project instead.

Although... well, if the Death Star, the size of a small moon, puts out as much energy as the sun in eight thousand years... *scratches chin*

[Ford Prefect]

Come back when he causes a skyscraper to collapse or snap in two. Then you might have problems, but your story will be judged on its meits as a story, not on how powerful a character in it is.

[Feil]

Pretty sure what you've described is impossible. Wouldn't the arm-shoulder-ribcage assembly squish together before any bones snapped, thereby making the punch just crunch him like a bird hitting an automobile? Why can't you just have him punch the guy's arm off with a straight punch?

[Davey]

<cut> ...but your story will be judged on its meits as a story, not on how powerful a character in it is.

Thanks, I understand.

I've read a lot about Gary/Mary-stu/sue and I don't want to make the same mistakes as all the rest of the kiddies on FanFiction.net. But this particular question focused on this small, little part of the story. I also agree, yeah, the story is what counts, the plot and and the strength of the story is my priority. But I don't like spreading plot summaries around unless I have to; doing that makes me feel kinda bad because I'm just telling, and not showing. It makes me feel like I'm just being lazy or something.

[Davey]

Pretty sure what you've described is impossible. Wouldn't the arm-shoulder-ribcage assembly squish together before any bones snapped, thereby making the punch just crunch him like a bird hitting an automobile? Why can't you just have him punch the guy's arm off with a straight punch?

That can be rewritten, then. If a punch that hard would just crumple the target, I suppose, well, if the laws say it should happen that way, I'll follow 'em. I've cut up lots of bones before (cooking), but those bones were dead and brittler than living bone, although I didn't know how much more, that's why I figured they'd break before squishing together into some organic pancake.

The robot is kind of evil. It crunches up the limbs of its opponents before it kills them. Then again... that can be changed as well...

[LadyTevar]

I can tell you that an archeology study of a medieval-period Viking grave found that the deceased's cause of death was caused by a massive blow to the hipbone, causing it to shatter and send bone fragments diagonally up through the body with enough force to embed themselves into the inside of the shoulderblade.
They believe it was an upward-arcing blow from a 'mass-weapon', such as a mace or an axe.

Thus, a blow of sufficient force can puliverize bones and send the splinters flying.

[Darth Wong]

It would probably be good to try and find pictures of car accident victims if you want to see what massive blunt-force trauma does to the human body.