Author Topic: How fast does one fall?  (Read 5852 times)

Offline behaigo

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How fast does one fall?
« on: December 02, 2011, 09:41:33 AM »
I'm just wondering about how fast someone falls when dropped from a great height? 
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Offline RobbyPants

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Re: How fast does one fall?
« Reply #1 on: December 02, 2011, 11:17:19 AM »
It depends on a lot of things. I thought gravity had an acceleration of 9.8 meters per second squared, but that's not counting for things like air resistance. Given that rounds are six seconds, you could fall pretty far in one round.

Edit:
I googled this and found that a rock is estimated to fall about 150m in six seconds. Another person estimated 480 feet, which is pretty close. Basically, if this is close to accurate, you'd hit D&D's terminal velocity of 20d6 damage within one round.
« Last Edit: December 02, 2011, 11:20:33 AM by RobbyPants »
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Offline altpersona

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Re: How fast does one fall?
« Reply #2 on: December 02, 2011, 11:22:07 AM »
 :shakefist

9.8 / 1^3

 :lmao

« Last Edit: December 02, 2011, 11:23:55 AM by altpersona »
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Offline SneeR

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Re: How fast does one fall?
« Reply #3 on: December 02, 2011, 11:24:48 AM »
In D&D? 250 ft per round, if I am not morbidly incorrect.
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Offline archangel.arcanis

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Re: How fast does one fall?
« Reply #4 on: December 02, 2011, 11:25:26 AM »
Just as a point of fact terminal velocity for a human body is about 121 MPH. And height to achieve this is about 500 ft. Those are the real world numbers calculated and tested by the Mytbusters for one of their myths.

Oh and Robby you are correct about acceleration due to gravity and it is 32 ft/s^2 if you want to use the imperial system instead of metric.

In game mechanics I think the DMG has how far you fall in a round under the flight mechanics, but I'm not sure.

Offline SneeR

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Re: How fast does one fall?
« Reply #5 on: December 02, 2011, 11:45:52 AM »
In answer to the thread name: "As fast as your paladin can tell a lie."
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Offline behaigo

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Re: How fast does one fall?
« Reply #6 on: December 02, 2011, 12:52:46 PM »
So it looks like after a person hits terminal velocity they will be falling about 1,000 feet per round.  About how long would it take to get to terminal velocity, and how far would they fall?
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Offline archangel.arcanis

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Re: How fast does one fall?
« Reply #7 on: December 02, 2011, 12:57:23 PM »
So it looks like after a person hits terminal velocity they will be falling about 1,000 feet per round.  About how long would it take to get to terminal velocity, and how far would they fall?
I already answered some of this but here is a full quote to get the rest of it down:
Quote
22,000 drop: The MythBusters knew human terminal velocity is 120 mph, so they decided to use balloons to lift their airman to an appropriate height for terminal velocity: 487 ft (5.5 seconds). They also planned on using a guide wire to direct airman's fall directly into the mock train station. (NOTE: In Escape Slide Parachute, they calculated with a 14 second fall and 2000 ft drop height)
Bolded for emphasis.

So conveniently they hit terminal velocity in almost exactly 1 round.

game mechanics wise here is your answer from the SRD:
Quote
Minimum Forward Speed
If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn.
This is for flying creatures who stall but I'd say the 300ft per round sounds good for game purposes.
« Last Edit: December 02, 2011, 01:00:40 PM by archangel.arcanis »

Offline darqueseid

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Re: How fast does one fall?
« Reply #8 on: December 02, 2011, 02:08:59 PM »
So this is an instance where d&d and real world don't mesh

Basically Terminal velocity in the d&d universe is after 200ft.  The rule being: 1d6 points of damage per 10 feet fallen, to a maximum of 20d6. (DMG)

Terminal velocity in the real world is ~122mph (converted to feet thats 179ft/sec) and it takes 500ft to reach it, however, that is a falling body with a random orientation.  Speeds of up to 600mph have been reached from skydivers orienting themselves into a low wind resistance shape. 

Accelleration increases asymptotically up to terminal velocity.  The above numbers of  122mph and 500ft are for real world wind resistance at the surface of the earth. 

to figure out how far somone falls from rest in a certain amount of time, you have to add things together,
approximating g as 32ft/sec^2 a person will gain 32feet of speed each second,
after one second his velocity is 32feet/sec and he has traveled 32feet. 
After two seconds his velocity is 64 feet/sec and he has traveled a total distance of 96 feet.  After 3 seconds his velocity is 96 feet/sec and he has traveled a total distance of  192 feet. 
4 sec, velocity is 128ft/sec, distance traveled is 320. 
5 sec , v=160, dt=  480
at somwhere between these times terminal velocity will be reached. (around 179 ft/sec-(122mph converted to feet/60/60)) (this math also supports mythbusters btw)
6 sec, v=178, dt = 658

and you can extrapolate from there. The point is, in d&d terms you will reach "terminal velocity  at half a round", whereas in real life it takes  a little more than 5 secs to reach terminal velocity.
remember, air density and gravitational factors may also play a part in accelleration, but for our purposes the above numbers are close.
« Last Edit: December 02, 2011, 02:33:57 PM by darqueseid »

Offline Kajhera

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Re: How fast does one fall?
« Reply #9 on: December 02, 2011, 02:24:37 PM »
150ft in the first round, then 300ft/round. Least, if you can fly.
"If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn."

Offline archangel.arcanis

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Re: How fast does one fall?
« Reply #10 on: December 02, 2011, 02:43:12 PM »
150ft in the first round, then 300ft/round. Least, if you can fly.
"If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn."
look up 2 posts.  :P

Offline Kajhera

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Re: How fast does one fall?
« Reply #11 on: December 02, 2011, 02:51:20 PM »
150ft in the first round, then 300ft/round. Least, if you can fly.
"If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn."
look up 2 posts.  :P
I'm sure I checked to see if anyone had said it. But I didn't think I was so slow at posting that it took me an hour to press the 'post' button there (/checking edit time) So I must be mistaken.

Offline archangel.arcanis

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Re: How fast does one fall?
« Reply #12 on: December 02, 2011, 02:57:12 PM »
150ft in the first round, then 300ft/round. Least, if you can fly.
"If a flying creature fails to maintain its minimum forward speed, it must land at the end of its movement. If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet. If it hits the ground, it takes falling damage. Otherwise, it has another chance to recover on its next turn."
look up 2 posts.  :P
I'm sure I checked to see if anyone had said it. But I didn't think I was so slow at posting that it took me an hour to press the 'post' button there (/checking edit time) So I must be mistaken.
It is all good. Just had to poke fun at you. Sadly that wasn't even the first time in this thread that I said something and someone else came and said the same thing a little while later.

Offline kitep

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Re: How fast does one fall?
« Reply #13 on: December 02, 2011, 03:21:34 PM »
They fall at the speed of plot  :lol

If a person falls a 150 feet, they should hit the ground at the end of their turn, by D&D rules.  But I'm quite willing to say they hit the ground at the start of his next turn, allowing his teammates a chance to rescue him.

Offline awaken_D_M_golem

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Re: How fast does one fall?
« Reply #14 on: December 02, 2011, 04:01:22 PM »
In answer to the thread name: "As fast as your paladin can tell a lie."
This is the correct answer  :cool.


Using a real world definition of "falling" but exclusive of real world physics ...
you could accelerate something via TK or whatever
to a ridiculously high number, like Chuck holding a Pixie
{ ... insert take that carnivore smiley face ... }
and heave it through a portal to the Quasi-Elemental Vacuum Plane (Air+Negative).
It could "fall" the whole way through the plane,
although the denizens there might not like it and intervene.
It's also possible the Plane would like the situation
and allow it to fall indefinitely ; never leaving the "boundaries" of the Plane.
 :D
Your codpiece is a mimic.