3000 mph punch

I want to know how strong is a punch at 3000 mph. What can my speedster punch through and what can't he punch through?

I also have character who can take the 3000 mph punch, with only minor injuries. What else could he survive with a durability like that?

At that speed it's basically a kinetic projectile (think railgun round).

The impact velocity is 1.3 km/s. If we approximate the mass of the hand+forearm at 1.5 kg, we get a kinetic energy of 1.27 MJ, equivalent to 0.3 kg of TNT.

For comparison, this is roughly the energy of an average car moving at 150 km/h (90 mph). Except it is concentrated on a much smaller surface.

If the character taking the hit weighs 100 kg (200 lbs), then the impact will send him flying backward at 20 m/s (45 mph)... or go through him. Note that the character throwing the punch will have the same problem with conservation of momentum, and will need a very stable stance to not knock himself backwards.

edited 16th Mar '16 5:46:36 PM by Aetol

Thinks, I'll look in to stances to help give him a good stance.

edited 16th Mar '16 5:49:56 PM by David

After reflexion... the only way he'd not fall over or slide backward is by anchoring himself to the ground. If he can't transfer the momentum to something fixed, he can't possibly throw such a punch correctly.

He's also at risk of falling forward if the punch doesn't connect (i.e. if he can't transfer the momentum to his target, it'll be transferred to him). So the anchorage needs to work both ways : simply having something push him in the back, for example, isn't enough.

Or you could just go the easy way and simply ignore physics when they are inconvenient like that.

One could do the robot rocket punch like this◊. Essentially, the fist detaches from the body to punch, then returns to the body.

edited 17th Mar '16 2:49:19 AM by hellomoto

He'd better have indestructibility along with his other super-powers, otherwise after one such punch, his fist would be turned into tomato puree.

He creates an energy shield that gets stronger the fast he moves, but it only surrounds the spot that's moving. This shield effectively makes him nigh invulnerable. This is why friction doesn't kill him every time he moves so fast.

edited 17th Mar '16 6:00:37 PM by David

That's not enough, though. Since his fist must accelerate over such a short distance (around 1 m), the internal forces within his arm will reach the millions of Newtons. It would utterly obliterate his articulations, bones, and muscles, unless his entire arm was indestructible.

edited 17th Mar '16 2:44:48 PM by Aetol

The shield is designed to absorb impact and is always three times stronger than he needs to move at his current speed. So if he moves at 100 mph the shield would be able to with stand and absorb enough of the force to withstand an impact at 300 mph.

EDIT: also he gets his powers from a magical mark. Anyone with a mark (regardless of the main power the mark gives) has super strength, (without the mark for strength they can only lift half a ton) high durability, (not anywhere near superman level) super speed, (without the mark for super speed they can only run up to 70 mph) and super senses.

EDIT AGAIN: I forgot about there high healing factor, again without the mark for healing it would take hours to heal something like a broken finger.

edited 17th Mar '16 4:40:56 PM by David

Just get a gun!

Also, how much stronger would the punch be if he took a running start first?

nice joke, but most of the people in this story would be able to counter a bullet, making a gun useless.

edited 17th Mar '16 10:23:15 PM by David

How does one counter a bullet in a manner that doesn't protect against a high-speed punch?

edited 17th Mar '16 10:29:50 PM by hellomoto

He's punching at 3000 mph and a bullet moves at about 1700 mph. All it'll take is abilities that can counter something moving at about 1700 mph, but not 3000 mph. To name a few that has proven to be faster than a bullet, but not the high speed punches are sand control, rock control, air control, water control, Teleportation (the teleportion is instantaneous, but he needs to actively attempt the Teleportation, which is faster than a bullet at a far enough distance, but not a high speed punch, which would have to be in arms reach to hit) and that durability that I mentioned earlier can semi protect from the bullet (I know it'll penetrate their skin, but it still wouldn't do as much to them as it would to a normal human.)

My main character also has fast enough reflexes and is fast enough to block a bullet with his sword (his sword is magically protected, so it won't take any damage and he has a mystical third eye that floats through the air that can track things at any speeds, even if his body can't keep up.)

That is just the powers that I can think of right now that can't easily counter a high speed punch. There are plenty that can counter the high speed punch too. Plus a gun has limited ammo and you can change a punches direction mid punch. Plus this is 1000 mph slower than his top speed, he's just more comfortable with moving at 3000 mph. Though there are some people that combo a gun with there abilities, one of which can make any thing attracted to anything. That attraction power works by converting the momentum of an object into the direction of another object (bullets that seek out the target.) Though that bullet could still be stopped by a rock wall moving in front of said target.

I am sorry for this post being so long.

Edit: those elemental control abilities can control those elements at the molecular level, effectively making even a thin layer of rock as strong as a five foot thick metal wall.

EDIT:One more thing, he could also hit someone or something with one finger at 3000 mph, which would be almost as if you got hit by a bullet moving at 3000 mph. That would do more damage than a normal bullet.

edited 18th Mar '16 1:16:36 AM by David

Unless his running speed is a significant fraction of 3000 mph, not at all.

No, it'll be 3000 mph with a top speed of 4000 mph.

Wait, maybe I misunderstood the whole thing. Is he able to throw a punch at 3000 mph while staying stationary, or does he run at 3000 mph while punching people on the way ?

The first question was about him throwing a stationary punch, but the sencod question was about him doing it while running at 3000 mph himself

edited 18th Mar '16 9:01:41 AM by David

Well, the velocities add up, but since he probably doesn't want to leave his fist behind after punching, he won't use up all the kinetic energy in the punch. How much exactly is hard to tell.

It would make the stability problem easier, I think, since the changes in momentum would just mean running a bit faster or slower (instead of going from 0 to some high high speed as before).

So if he was running while he punched someone, it'll be slightly weaker, but less likely to throw him back.

edited 18th Mar '16 9:05:58 AM by David

It's not even necessarily weaker. It just won't be four times stronger, even though his fist has four times the kinetic energy (because it needs to retain some velocity afterward).

So the same or stronger, but more stability. Then he'll mostly punch while running.

How's his accuracy? Wouldn't want to miss at that speed.

His brain can process things far faster than a normal human. To compare it to a normal human, running at 2000 mph for him would be like driving a car at 50 mph for a human. This means 3000 mph would be like 75 mph and 4000 mph like 100 mph. Either way he can't turn easily, but at 3000 mph he can tell where he's going. At 4000 mph it's harder, but he can still hit something with a good accuracy. So if you were able to react fast enough you could make him miss easily, but not many people could react fast enough to dodge him at that speed. What I'm trying to say is he has a good enough reaction speed that he'll be able to tell what he's running at and not many people could get out of the way in time, unless he was running at them from a far enough distance away.

Sorry for the long wait, I was without Internet for a couple of days.

edited 20th Mar '16 11:03:06 PM by David