What tier is surviving atmospheric reentry?

[DeathstroketheHedgehog]

This something I encounter a lot but do not know the answer to.

 

[WeeklyBattles]

Depends on what's surviving it but for a human surviving reentry it's Building level

 

[DeathstroketheHedgehog]

Depends on what's surviving it but for a human surviving reentry it's Building level

Do you know where you got this calculation from? I may try using it with this three mile tall character I know.

 

[Gwynbleiddd]

If there was no atmosphere then the kinetic energy of a human hitting the ground would be Small Building level to Small Building level+ depending on the mass of the human.

But since the atmosphere is there, the human would slow down till he reached terminal velocity which depending on the way he is falling would be 30-100 m/s making the feat Wall level.

 

[DeathstroketheHedgehog]

May I get a mathematical equation for this?

 

[Lina_Shields]

• Minimum impact speed of incoming objects/meteors heading towards Earth = 11.2km/s
• Minimum impact speed of incoming objects coming from the Sun/deep outer space = 72km/s

So depending on where said person in question is being dropped from, we can find two answers for this.

• Using "mass of human" = 100kg
• Using the kinetic energy equation
• KE (minimum impact velocity) = 0.5*(mass of human)*(11200^2) = 6.272e9 Joules, or 1.5 Tons of TNT. Large Building level
• KE (if person is being hurled from outer space) = 0.5*(mass of human)*(72000^2) = 2.592e11 Joules, or 61.95 Tons of TNT. City Block level+

The minimum impact velocity varies depending on the size and the surface gravity (mass and density of said planet affects this) of the planet in question, but the kinetic energy here applies to planets w/similar size and gravity as Earth.

 

[Gwynbleiddd]

https://vsbattles.fandom.com/wiki/User_blog:DontTalk/Surviving_a_fall_from_low_Earth_orbit

 

[Matthew_Schroeder]

I always saw this getting Building level, yes.

 

[Antvasima]

We should preferably link to DontTalk's blog in one of our calculation instruction pages.

 

[Antvasima]

Never mind. I have inserted a link to DonTalk's calculation in the footnote section of the Durability page.

 

[Lina_Shields]

Just need to stress this: Why is the gravitational potential energy used for this when the OP does not state where said person is falling from.

• For DontTalk's High end of the calculation, why is the height of the person and the surface of the Earth 160km? If they are falling down from outer space, and atmospheric re-entry occurs from that, said height should be much higher.

The main question here is, is the terminal velocity of a falling human always going to be 30 to 100m/s despite the distance between the falling person and the Earth?

 

[Matthew_Schroeder]

Yeah, DontTalk's calc is very lowballed. IT says "Low-Atmosphere" for a reason.

Feats of falling from outer space are generally Building level.

 

[Lina_Shields]

I still don't see why the terminal velocity via falling from outer space directly to Earth isn't equal to the surface escape velocity, as the speed to escape Earth's orbit = speed of entering Earth's orbit.

Shouldn't it still be 11.2 km/s? Using that speed value, you would be getting Large Building level for it, not Building level.

 

[Antvasima]

As far as I understand, the terminal velocity is the official calculated number of the maximum falling speed for a human being (as opposed to, for example, a meteorite) down to the Earth, due to atmospheric friction.

 

[Lina_Shields]

So I have checked out this page here, and you are correct that the terminal velocity of falling objects varies.

• However, the drag coefficient value depends on the shape of the falling object, which will cause the terminal velocity of said object to vary.
• The page that I have listed above does not state anything about the mass of the falling object, although the mass of the object would not matter too much in this case as all objects that fall from a specified height accelerate at the same rate from peak height to ground level.

 

[Antvasima]

Okay.

 

[FateAlbane]

@OP I once had the same question and calced the fall of a character of mine.

It was calced as 63, 02 tons of TNT or City Block+ . Though I don't know if the same conditions of the fall would apply to the OP's question. Just giving an example of sorts.

Granted it was my first calc ever so it may be inaccurate.

 

[Lina_Shields]

I believe this topic is dealing with the kinetic energy with air resistance factored in, so the resistance of Earth's atmosphere would cause said object to slow down drastically.

This is because falling object here is actually pushing through said resistance while continuing to fall, thus reducing its kinetic energy, therefore its speed.

Your calculation does not factor in air resistance, thus the velocity of the falling object would increase tremendously, thus the KE also increases.

 

[FateAlbane]

@Lina That makes sense.

But wait, if the air resistance slows it down that much, does the person being hurled from outer space still hit Earth with City Block+ because of...?

Speed? Distance? I'd like to understand that better so I can make my own comprehension of how these things work better in the future too and stuff.

 

[Antvasima]

As far as I understand, DontTalk's calculation is for characters that fall from outer space, only accelerated by the Earth's gravity, not ones hurled at far greater speeds.

 

[Lina_Shields]

DontTalk's calculation uses the height of Low Atmosphere, which is far below the height of outer space (which exceeds over 1000km in terms of height).

 

[FateAlbane]

So depending on where said person in question is being dropped from, we can find two answers for this.

• KE (if person is being hurled from outer space) = 0.5*(mass of human)*(72000^2) = 2.592e11 Joules, or 61.95 Tons of TNT. City Block level+

The minimum impact velocity varies depending on the size and the surface gravity (mass and density of said planet affects this) of the planet in question, but the kinetic energy here applies to planets w/similar size and gravity as Earth.

@Ant Rereading and paying attention to this particular answer Lina made, I understood how this works.

Thanks in advance, now I get it.

 

[Antvasima]

@Lina Okay.

@All Has this thread been properly dealt with? If so, it might be a good idea to close it.

 

[Golden_Void]

OP has disappeared so yeah.

 

[Lina_Shields]

Sure. Let's do just that.

Closing this thread.