/sci/ - Science & Math

>>5370718
depends on how fucking fat you are.
for you, i'd say a couple of stories should do it.

i feel bad for all the earthquake victims though...

Check out "terminal velocity", and then consider the importance of blunt impact (the killer) versus getting lots of g-force due to deceleration when you hit the ground (the anaesthetic).

But also see http://en.wikipedia.org/wiki/Vesna_Vulovi%C4%87
>surviving the highest fall without a parachute: 10,160 metres

>>5370725
>10,160 metres
Oh fuck

>>5370724
hey you're back. learn calculus over your break yet?

>>5370725
>Check out "terminal velocity"
You can bypass terminal velocity quite easily. Fill a backpack with 30 kgs of lead bricks or whatever amount you can carry and you'll have a larger density, increasing terminal velocity.

>>5370724

I'm the real EK.

>>5370724
If that is actually you, I regret to inform you that your 4/10 looks do not justify your raging narcissism.

If it isn't you, why don't you find someone more attractive to post?

>>5370755
>Fill a backpack with 30 kgs of lead bricks or whatever amount you can carry and you'll have a larger density, increasing terminal velocity.
Ah, I never thought about that.

>>5370751
maille... on my /sci/?

>>5370755
No. Terminal velocity does not work that way.

>>5370828
Why not? With increased mass per volume you should accelerate to a higher velocity because the gravitational force is stronger than the drag, relative to the scenario without the extra mass.

>>5370835
The buoyant force, which is the only thing that will be affected by the extra mass (gravitational force drops out), is negligible here. It's extremely important when you sink in water, but not when going through air.

The force of drag on your body looks like A*v^2, where A is your cross-sectional area to the wind (ground face). So the best bet is to swan-dive that thing.

Now I will backtrack and say you *should* add weights to your body. It won't increase your velocity in the fall, but it will increase greatly your momentum when you hit the ground, such that you're much more likely to impact your skull at full speed before you decelerate too much from your hands or body or whatever.

>>5370851
>The buoyant force, which is the only thing that will be affected by the extra mass (gravitational force drops out)

That's wrong. Increasing weight increases weight. It doesn't "drop out." Terminal velocity is when weight = drag. Increasing weight more than you increase drag decreases terminal velocity. Parachutes don't work based on buoyant force, they work by increasing drag more than weight. Carrying a bag of bricks is just the converse of that.

>>5370859
You're right - that was dumb of me - my bad.

>>5370859
It's almost as if you think a mass affects the acceleration of free-fall

>>5370875
wat.

>>5370875
It doesn't affect the acceleration, but it affects terminal velocity and momentum of impact.

Am I getting this right that terminal velocity matters only if you jump from a great height, but you don't achieve terminal velocity in normal jumps (from buildings and such)?

>>5370724
>doesn't capitalize I
confirmed for angsty teen.

pic unrelated.

>>5370875
let's get some formulaes in here

you're accelerating force is c*dm (c is some constant, it doesn't matter which in this case, dm ist the mass difference between you and the medium of equal volume (this is where buoyancy comes from))

the actual acceleration is of course F/m, which is why the mass doesn't matter in a vaccuum

your decelerating force is simply the drag which is hard to model but it's roughly independant of your mass, proportional to v^2, where v is you relative velocity, and very much dependent on the shape your body, the surface of your body and the viscosity of the surrounding medium

all this means that your acceleration is (Fa - Fd)/m. Fa increases with your mass and Fd doesn't. Thus you should increase your mass if you want to fall faster.

If you don't know at least this you should never psot in a physics thread.

>>5370907
If you jump down from 10 meters, your velocity at impact will be around 50km/h. Terminal velocity is at around 200km/h. Since drag scales with the square of you velocity, that means that at 50km/h you're accelerating only 15/16 as much as if you were in a vaccuum. So it's measurable but not that important at that height.

I don't think there's any height that'll kill you instantly. There's people who've survived falls that reached terminal velocity

>>5370962
Depends a lot on the kind of ground you fall on. I wouldn't attempt suicide by falling on soft dirt. Those people survived because of optimal conditions.