LS from KE

[Expectro2000xxx]

I have a certain feat in which a character throw an object (with a stated weight) at certain speed (the speed of the character was stated in the same scene) and with that I calculated the kinetic energy using a calculator, I saw before that one can get LS from kinetic energy so I want to know how to do so.

 

[Noneless21]

Isn't this more suited at calc group forum?

 

[Arceus0x]

i don't think you can get it from kinetic energy. You can, however, take the weight of the object and calculate the acceleration. You'd need to calc acceleration first though.

 

[Gilad_Hyperstar]

You can't directly convert KE to newtons, but you could calculate the acceleation of whatever is moving or being thrown, as well as calculating the mass to get the force

I'll provide an example: Assume you got a 2 tons cube being thrown at character A at a speed of 100 m/s

KE would be: E = 2000 * 100^2 = 20,000,000 joules

Now, say it took Character A 1 second to completely stop the cube in its tracks

That would give us a timeframe of 1 second

A = 100/1 = 100 m/s^2

F = M * A = 2000 * 100 = 200,000 Newtons or 20,387.36 kg which is Class 25

 

[KLOL506]

After you get the acceleration, you must show evidence that the character kept pushing/wrestling against the object even after bringing it to a halt.

 

[Gilad_Hyperstar]

After you get the acceleration, you must show evidence that the character kept pushing/wrestling against the object even after bringing it to a halt.

Yes, since that's how they get the LS in the first place. Though if something is immediately stopped in its tracks or being instantly restrained by another character, that also works

 

[KLOL506]

Yes, since that's how they get the LS in the first place. Though if something is immediately stopped in its tracks

Nah, this part you'd have to show they're still pushing against it even after it stops, palms open and attempting to grab it (Like here, where Hulk punches into a Leviathan but it isn't enough to completely halt it so he keeps applying pressure with his fist by pushing against it and not just punching it again, this is LS, or like All Might and Deku stopping a big ass cubiod from slamming onto them with a punch but then they still keep pushing against it afterwards because otherwise gravity would do the work and make it fall down regardless). Otherwise it's AP.

or being instantly restrained by another character, that also works

If the restrained character is then unable to break free even after constant struggling, sure.

 

[Expectro2000xxx]

Honestly I ask because there is a certain feat about a character grabing a tank, then the character used it like a hammer to do a big swing to hit missiles and throw the tank against an Apache Longbow helicopter flying between buildings, then both the helicopter and tank go through a building and continued to fly to the distance even after pass through the building.

The scene happen in a book so I don't visuals to know how much it took, just that the character grabbed the tank and instantly did a big swing making the scene.

I know however the weight of the tank since it was stated that is was more than 40 tons (and based in how the wiki say that the average tank weight 50 tons I believe is a safe number to use), I know the speed of the character since just a few paragraph before the character stated that she would be problems trying to actually get hit by bullets that aren't even from railguns (this while dodging a bullet rain from all directions without be graced, this from weapons like Howa Type's 89 who have a muzzle velocity of 920 m/s. Average military railgun speed are 2750 m/s, at least based in wikipedia). How should I do in this case? Want to know because there actually are more feats like this in the work.

 

[KLOL506]

Honestly I ask because there is a certain feat about a character grabing a tank, then the character used it like a hammer to do a big swing to hit missiles and throw the tank against an Apache Longbow helicopter flying between buildings, then both the helicopter and tank go through a building and continued to fly to the distance even after pass through the building.

The scene happen in a book so I don't visuals to know how much it took, just that the character grabbed the tank and instantly did a big swing making the scene.

Textbook LS and AP. Swinging and throwing work that way.

I know however the weight of the tank since it was stated that is was more than 40 tons (and based in how the wiki say that the average tank weight 50 tons I believe is a safe number to use), I know the speed of the character since just a few paragraph before the character stated that she would be problems trying to actually get hit by bullets that aren't even from railguns (this while dodging a bullet rain from all directions without be graced, this from weapons like Howa Type's 89 who have a muzzle velocity of 920 m/s. Average military railgun speed are 2750 m/s, at least based in wikipedia). How should I do in this case? Want to know because there actually are more feats like this in the work.

Well you could try momentum. He'd have to swing the tank from rest so you know what to do.

 

[Expectro2000xxx]

Textbook LS and AP. Swinging and throwing work that way.


Well you could try momentum. He'd have to swing the tank from rest so you know what to do.

Yeah, that's why I want to calc it, specially since the character current LS is relatively low.

Actually, no, I don't know what to do, just recently is that I'm trying to learn how to calc things in general so, how I should do it?

 

[Gilad_Hyperstar]

Nah, this part you'd have to show they're still pushing against it even after it stops, palms open and attempting to grab it (Like here, where Hulk punches into a Leviathan but it isn't enough to completely halt it so he keeps applying pressure with his fist by pushing against it and not just punching it again, this is LS, or like All Might and Deku stopping a big ass cubiod from slamming onto them with a punch but then they still keep pushing against it afterwards because otherwise gravity would do the work and make it fall down regardless). Otherwise it's AP.


If the restrained character is then unable to break free even after constant struggling, sure.

Sure. Just blocking isn't enough, but if they show that they push against it (or that the thing struggles to move forward while the other character doesn't budge), then it counts and is viable

 

[KLOL506]

Yeah, that's why I want to calc it, specially since the character current LS is relatively low.

Actually, no, I don't know what to do, just recently is that I'm trying to learn how to calc things in general so, how I should do it?

Momentum.

M1V1= M2V2

 

[KLOL506]

Sure. Just blocking isn't enough, but if they show that they push against it (or that the thing struggles to move forward while the other character doesn't budge), then it counts and is viable

Exactly.

Another decent example be here (Saejima looks at an oncoming car and stops it dead in its tracks, then the car keeps accelerating and Saejima wrestles against its torque long enough to safely get away from being run over).

 

[Expectro2000xxx]

Momentum.

M1V1= M2V2

So

Weight: 50,000kg
Velocity: 2,750m/s

KE: 50,000 * 2,750^2 = 378,125,000,000 joules (8-B)

P: 50,000 * 2,750 = 137,500,000 Ns.

LS would be 1,375x10^8 Ns (Class M), correct?

 

[KLOL506]

So

Weight: 50,000kg
Velocity: 2,750m/s

KE: 50,000 * 2,750^2 = 378,125,000,000 joules (8-B)

P: 50,000 * 2,750 = 137,500,000 Ns.

LS would be 1,375x10^8 Ns (Class M), correct?

Wait, I thought the tank was used to stop the tank

M1V1= M2V2 would be like this

M1 and V1= Apache Helicopter's mass and it's speed when it gets whacked

M2 and V2 = Tank weight and tank swinging speed

If there is already a speed given for how fast they swing the tank (2750 m/s, which you have to show evidence for whether they really swung it that hard), then you don't need momentum anymore, you should just shift straight to acceleration and F= ma

Acceleration= (Final Speed - Initial Speed/Time Taken) where in this case the initial speed is 0 due to the tank being at rest before being swung hard.

F= mass x acceleration

Timeframe is gonna be the tricky part, so I think you can start by looking for timeframes of IRL baseball bat swings.

Also KE is 0.5 * mass * velocity^2.

 

[Expectro2000xxx]

Wait, I thought the tank was used to stop the tank

M1V1= M2V2 would be like this

M1 and V1= Apache Helicopter's mass and it's speed when it gets whacked

M2 and V2 = Tank weight and tank swinging speed

If there is already a speed given for how fast they swing the tank (2750 m/s, which you have to show evidence for whether they really swung it that hard), then you don't need momentum anymore, you should just shift straight to acceleration and F= ma

Acceleration= (Final Speed - Initial Speed/Time Taken) where in this case the initial speed is 0 due to the tank being at rest before being swung hard.

F= mass x acceleration

Timeframe is gonna be the tricky part, so I think you can start by looking for timeframes of IRL baseball bat swings.

Also KE is 0.5 * mass * velocity^2.

According to this a baseball swing require a full 150 miliseconds to complete, which converted to seconds is 0.15s. So it would be like this:

Acceleration = 2,750/0.15 = 18,333.333 m/s^2

F = 50,000 * 18,333.333 = 916,666,650 Newtons (Class M)

KE = 05 * 50,000 * 2,750^2 = 189,062,500,000 Joules (8-B)

 

[KLOL506]

According to this a baseball swing require a full 150 miliseconds to complete, which converted to seconds is 0.15s. So it would be like this:

Acceleration = 2,750/0.15 = 18,333.333 m/s^2

F = 50,000 * 18,333.333 = 916,666,650 Newtons (Class M)

KE = 05 * 50,000 * 2,750^2 = 189,062,500,000 Joules (8-B)

Okay, is there any scan that says the tank is hurled at 2.75 km/s or Mach 8? Or any statements saying "swung as fast as a railgun round" or something similar like where the railgun round is seen as slow whereas the tank near it is being swung faster in dilated time?

Because otherwise, we can't use that speed for swinging.

 

[Expectro2000xxx]

Okay, is there any scan that says the tank is hurled at 2.75 km/s or Mach 8? Or any statements saying "swung as fast as a railgun round" or something similar like where the railgun round is seen as slow whereas the tank near it is being swung faster in dilated time?

Because otherwise, we can't use that speed for swinging.

The entire scene is like this:

The sight there was the tanks that were the strongest steel weapon above ground being sent flying as though they were tree leaves that got blown away by wind. They were overturned or crushed.

「The stress of beging chased around everywhere by the police officers! I’ll vent it here desuuu!」

The huge warhammer were sending everything flying. It didn’t matter whether it was a tank that weighed more thn 40 tons, or a speedy combat vehicle, or a fully armed soldier, they all flew the same.

The opponents were just virtual image in the end. They were nothing more than puppets reproduced from vast amount of records and Hajime’s memory.

That was why Shia had zero hesitation in going town on them.

Tearing them to shreds and threw, tearing them to shreds and threw, mass producing stains on the ground, punching through a the frame of a nearby car and then grabbing it to throw it with her physical strength like a cannonball. It was truly the side of a man-eating fiendish rabbit.

『Shia! Be careful to the bullets! Thy magic power would be dispersed if they hit──』

「The bullets aren’t even electromagnetically charged! The soldiers aren’t predicting my action to fire at where I’m going to move! It will be harder for me to try to get hit by such bullet desuu!」

It seemed to be difficult for her. In fact, with her steps that pulverized the ground with each step and her rapid braking, her “Air Force” boots, and furthermore her three dimensional movement that made use of building’s wall and every surface around her, she was dodging everything. She hadn’t even been grazed. Even though the enemy was laying out a really fierce barrage, it looked like the bullets were avoiding her instead.

Even now she was producing something like afterimages behind due to her free movement and fiercely varying tempo. Then right at the next instant, a soldier got punched on the gut and he was sent flying toward the building at the side.

In order to stop Shia who was moving like a storm like that, the attack helicopter that appeared from between the buildings fired countless rockets on her.

「Too easyyy! Desuu!」

Together with 「desuu」 that sounded like it was only added as an afterthought, Shia grabbed the turret of a toppled tank with all her strength.

「FUNNUAAAAAAAAAAAAH!」

She performed a giant swing with that tank. The tank that became a giant warhammer for Shia deflected all the rockets. And then using the centrifugal force she immediately threw the tank.

「Fly away until the moon! Desu!」

It impacted the attack helicopter. The tank pulverized a wall together with the helicopter and flew inside the building. A second later there was a thunderous sound from the opposite side of the building and the two vehicles flew out. Arifureta Blu-ray SS, Chapter 4 – Eternal Artifact

Is stated how it's difficult to her get hit by bullets that aren't electromagnetically charged (this since the character fight all the time against Hajime who use railguns as weapons), she wasn't even graced by barrage from all sides from the japanese military force which use as standard weapon Howa Type 89 (which muzzle velocity is 920 m/s), and additionally is said how she is stressed and don't hold back.

 

[KLOL506]

The entire scene is like this:


Is stated how it's difficult to her get hit by bullets that aren't electromagnetically charged (this since the character fight all the time against Hajime who use railguns as weapons), she wasn't even graced by barrage from all sides from the japanese military force which use as standard weapon Howa Type 89 (which muzzle velocity is 920 m/s), and additionally is said how she is stressed and don't hold back.

Rockets eh? Try using rocket speed instead. What kind of rockets we dealing with here? I know some that do Mach 1.2 and shit.

 

[Expectro2000xxx]

Rockets eh? Try using rocket speed instead. What kind of rockets we dealing with here? I know some that do Mach 1.2 and shit.

Is really necessary to use the rockets speeds when she herself state that unless is a railgun it would be hard for her to get hit (which is both consistent with the scene and story as she can dodge Hajime railguns)? I could however if really necessary use the rockets speed. An Apache 64 is typically armed with a mixture of AGM-114 Hellfire missiles (444.72 m/s) and Hydra 70 (739 m/s) rocket pods, both things are slower than the Howa Type 89 (920 m/s) used by the soldiers in the heavy barrage to hit the character.

 

[KLOL506]

Is really necessary to use the rockets speeds when she herself state that unless is a railgun it would be hard for her to get hit (which is both consistent with the scene and story as she can dodge Hajime railguns)? I could however if really necessary use the rockets speed. An Apache 64 is typically armed with a mixture of AGM-114 Hellfire missiles (444.72 m/s) and Hydra 70 (739 m/s) rocket pods, both things are slower than the Howa Type 89 (920 m/s) used by the soldiers in the heavy barrage to hit the character.

We use only the speeds with direct showings, not those of hypothetical scenarios unless demonstrated.

 

[Expectro2000xxx]

We use only the speeds with direct showings, not those of hypothetical scenarios unless demonstrated.

I mean, we also take that statements have priority (at least as far I have saw before), the statement also don't contradict the context since a fierce barrage of bullets come from all direction flying at 920 m/s can't even grace her.

From what I know there is a problem with using speeds from other scenes at the moment of calc a different fight, but in this case the statement happen in the exact same fight of the feat, just 8-9 paragraphs before the end of the feat.

 

[Expectro2000xxx]

Putting aside the speed used (since this probably isn't the place to talk about that), is the math itself correct?

 

[KLOL506]

Lemme do the math using the Howa Type 89 bullets.

KE: 0.5 * 50000 * 920^2= 2.116e+10 J or 5.057361376673 tons of TNT (High 8-C)

Acceleration: (Final Speed - Initial Speed)/Time taken

150 milliseconds is 0.15 seconds

Acceleration: (920-0)/0.15= 6133.33333333 m/s^2

F= ma so 50000 * 6133.33333333= 306666666.666 N or 3.127129719798535e+7 kgf (Class M)

 

[Expectro2000xxx]

If the math is correct then I will put it in a blog.

 

[Expectro2000xxx]

Posted the calc with both ends.