Drop a bullet vs. Shoot a bullet

[exdeath]

Aside from the obvious problems like the curvature of the earth, etc., I don't know if these were mentioned:

The bullet leaving the rifle will have an initial upward velocity (typical parabolic ballistic path).

Also the tremendous forward velocity and the aerodynamic shape of the bullet in flight could possibly act as a limited lift surface to oppose gravity at its highest velocities.

So I'd say the dropped bullet would hit the ground first.

 

[Sixtyfour]

Originally posted by: akubi
well if you consider the curvature of the Earth and its rotation, the answer isn't as trivial as you might think

And that is not all of it.

Bullet has a shape and due to high velocity it creates bodylift, just like hypersonic cruisemissiles can fly without actual wings (body will work as a wing).

 

[The Pentium Guy]

WTF? I came here and to my dissapointment, there was no poll!

 

[The Pentium Guy]

Oh.... heh. I read this totally wrong. I thought the bullet was being fired at the ground. I'm like "WTF ARE YOU GUYS ARGUING ABOUT?"
Pretty good question actually.... ----> but it's a useless question without a poll <----.

It depends on how far out the gun shoots the bullet. If the gun is all-powerful, dropping the bullet would probably be quicker of course. If it was some weak pos gun then it would curve a bit and then fall - so I'd STILL say dropping it is better.

-TPG

 

[LongCoolMother]

there are really wayyyyy to many factors to take into account for realistically. theoretically, both bullets would hit the ground at the exact same time. the force acting upon both bullets in the y-component/vertical component plane is exactly the same, g/gravity.

so theoretically, both will hit at the exact same moment.

realistically? probably the dropped bullet due to air resistance, gravitation variability to name a few.

 

[Fuzb0]

Originally posted by: LordMorpheus

Originally posted by: RaynorWolfcastle

Originally posted by: Kyteland
The dropped one. Since the earth is a sphere, and not flat, the fired bullet will actually have farther to fall than the dropped one.

Note that this assumes that it is fired in a vacuum.

LOL, you want to ignore air resistance and the fact that terrain isn't flat but you want to take into account the fact that the Earth's surface is curved?

You must be a mathematician or a physicist

You can't shoot a firearm in a vacuum!!!!!!

sure you can, the primer ignites the charge in a sealed cartridge, you can fire a firearm in a vacuum or underwater. For safetys sake , do not fire a firearm underwater, Not just any gun can take the extra pressure. (think of the water as a cork at the end of your barrel)

EDIT
OOps scrolled to the bottom and saw this as the las t post... ill quit beating a dead horse now that ive read the entire thread throughout

 

[Eli]

Originally posted by: spacejamz
Let me ask it this way then...

let's increase the height from 4' to 10'...which one would you rather be under? the bullet being dropped or the bullet being fired from the gun?

the bullet being dropped might cause a bruise or something, but probably won't penetrate your skin. However, the result from the bullet being fired from the gun would be significantly different...pretty sure the bullet would pretty much go right through you...

Is this an accurate example?

Dear lord.. I'm only on the 1st page, but this thread is 3 pages long.. I hope you figured it out.

 

[hehatedme]

I dunno if this was said before (I only read a few pages of the thread), but I think the reason that the bullet shot from the gun won't hit the ground first is because it rotates around its x-axis because the barrel of the gun usually has grooves. That's what gives a bullet a straighter path than older muskets that somewhat lobbed bullets.

 

[sonoma1993]

i took 2 year of physics class. it funny reading half the answer in this post that are wrong. In a perfect enviroment, both bullets will hit the ground at the same time. But in the real world, the time diffrence will probably be just hundreds or thousands of a second when both bullets hit the ground. Like someone said earlier, gravity is pushing down on both bullet at 9.81m/s.

 

[91TTZ]

Originally posted by: sonoma1993
i took 2 year of physics class. it funny reading half the answer in this post that are wrong. In a perfect enviroment, both bullets will hit the ground at the same time. But in the real world, the time diffrence will probably be just hundreds or thousands of a second when both bullets hit the ground. Like someone said earlier, gravity is pushing down on both bullet at 9.81m/s.

Read the whole thread, and read a few pages back where we solved this mathematically. The curvature of the Earth will add a couple inches to the shot bullet's fall. The dropped bullet will need to fall 4 feet, while the shot bullet will need to fall 4 feet and a couple inches due to the amount of Earth curvature under the bullet which just traveled horizontally a few thousand feet.

 

[Nitemare]

Dropped bullet, because it will rotate nose down and become more aerodynamic with respect to gravity and fall faster.

 

[Armitage]

Originally posted by: exdeath
Aside from the obvious problems like the curvature of the earth, etc., I don't know if these were mentioned:

The bullet leaving the rifle will have an initial upward velocity (typical parabolic ballistic path).

Where exactly does that upward component of the velocity come from???

Also the tremendous forward velocity and the aerodynamic shape of the bullet in flight could possibly act as a limited lift surface to oppose gravity at its highest velocities.

The bullet is symmetric - no lift regardless of how fast it goes.

 

[LeiZaK]

Originally posted by: Armitage
The bullet is symmetric - no lift regardless of how fast it goes.

The OP said nothing about the bullet being symmetric. Furthermore, symmetry alone has no lift-cancelling effects AFAIK.

 

[Armitage]

Originally posted by: LeiZaK

Originally posted by: Armitage
The bullet is symmetric - no lift regardless of how fast it goes.

The OP said nothing about the bullet being symmetric. Furthermore, symmetry alone has no lift-cancelling effects AFAIK.

A body that is symmetric WRT the air flow cannot generate lift. A symmetric body can generate lift if it is oriented to have an angle of attack WRT the air flow. But then it isn't symmetric wrt the air flow.

AFAIK all bullets are symmetric about the long axis. If it's tumbling it will generate lift, but in constantly changing directions as it rotates.

 

[exdeath]

Originally posted by: Armitage

Originally posted by: exdeath
Aside from the obvious problems like the curvature of the earth, etc., I don't know if these were mentioned:

The bullet leaving the rifle will have an initial upward velocity (typical parabolic ballistic path).

Where exactly does that upward component of the velocity come from???

Also the tremendous forward velocity and the aerodynamic shape of the bullet in flight could possibly act as a limited lift surface to oppose gravity at its highest velocities.

The bullet is symmetric - no lift regardless of how fast it goes.

Upward component due to parabolic ballistic path typical of shot bullets. Guns do not shoot straight, as can be observed trying to hit a target at 100+ yards with a hand gun and having to aim up to try to 'throw' the bullet out there as high as possible.

I did say *possibly* lift due to angle caused by this parabolic path and tumbling? Depends on the bullet type (boat tail, etc). Just some ideas.

 

[Doboji]

oh for godsakes people, go try it... the dropped bullet hits the ground first.... the fired bullet gets some lift from it's mass and velocity, + the earth is curved.

/thread

 

[KokomoGSTmp]

Originally posted by: munky
Actually the dropped bullet would hit the ground first because everyone knows time slows down when bullets are shot. Ok, maybe not, but wouldnt it be cool if it did?

Relativity can apply if gun is powerful enough. RAIL GUN!!!

Oh and if you factor air resistance... you might want to also factor in rifling and the spin of a bullet. This is assuming still air.

 

[Armitage]

Originally posted by: exdeath

Originally posted by: Armitage

Originally posted by: exdeath
Aside from the obvious problems like the curvature of the earth, etc., I don't know if these were mentioned:

The bullet leaving the rifle will have an initial upward velocity (typical parabolic ballistic path).

Where exactly does that upward component of the velocity come from???

Also the tremendous forward velocity and the aerodynamic shape of the bullet in flight could possibly act as a limited lift surface to oppose gravity at its highest velocities.

The bullet is symmetric - no lift regardless of how fast it goes.

Upward component due to parabolic ballistic path typical of shot bullets. Guns do not shoot straight, as can be observed trying to hit a target at 100+ yards with a hand gun and having to aim up to try to 'throw' the bullet out there as high as possible.

The OP stated that the gun was fired parallel to the ground. There is no upward component.

You add an upward component relative to the line of sight to a target because the bullet is falling as soon as it leave the barrel. But there is no target here.

I did say *possibly* lift due to angle caused by this parabolic path and tumbling?

The parabolic path has nothing to do with it. The bullet never has an angle of attack to the air flow anywhere during the flight. Unless it tumbles, in which case its random and is as likely to go down as up.

Depends on the bullet type (boat tail, etc). Just some ideas.

Unless you know of some bullet type that isn't symmetric about the long axis, and isn't spun by rifling, and is oriented the right way when fired.

 

[Armitage]

Originally posted by: Doboji
oh for godsakes people, go try it...

LoL - it'd be quite the setup to verify this experimentally. I believe the earlier calculations showed a difference in the thousandths of a second. I'm sure the average ATOT'r can just head out with a stop watch and a squirrel gunand verify it for you this afternoon

the dropped bullet hits the ground first.... the fired bullet gets some lift from it's mass and velocity, + the earth is curved.

WTF did this whole bit on lift come into it??
There is no lift.

/thread

The thread ended back about page 2

 

[Triumph]

Originally posted by: 91TTZ

Originally posted by: sonoma1993
i took 2 year of physics class. it funny reading half the answer in this post that are wrong. In a perfect enviroment, both bullets will hit the ground at the same time. But in the real world, the time diffrence will probably be just hundreds or thousands of a second when both bullets hit the ground. Like someone said earlier, gravity is pushing down on both bullet at 9.81m/s.

Read the whole thread, and read a few pages back where we solved this mathematically. The curvature of the Earth will add a couple inches to the shot bullet's fall. The dropped bullet will need to fall 4 feet, while the shot bullet will need to fall 4 feet and a couple inches due to the amount of Earth curvature under the bullet which just traveled horizontally a few thousand feet.

So what, no elementary physics book in the world is going to ask a Physics 101 student to incorportate the curvature of the earth. The answer is that they will land at the same time.

 

[mindmaniac]

Same, this is a good post

 

[91TTZ]

Originally posted by: Triumph

So what, no elementary physics book in the world is going to ask a Physics 101 student to incorportate the curvature of the earth. The answer is that they will land at the same time.

We live in the real world, not in an elementary physics textbook. And besides, who said anything about an elementary physics textbook? We aren't talking about school kiddies here. Who cares what an elementary physics textbook says? School only prepares you for the real world, so real world > simplified book. This is the real world, not physics 101. In the real world, the earth isn't flat.

 

[Triumph]

Originally posted by: 91TTZ

Originally posted by: Triumph

So what, no elementary physics book in the world is going to ask a Physics 101 student to incorportate the curvature of the earth. The answer is that they will land at the same time.

We live in the real world, not in an elementary physics textbook. And besides, who said anything about an elementary physics textbook? We aren't talking about school kiddies here. Who cares what an elementary physics textbook says? School only prepares you for the real world, so real world > simplified book. This is the real world, not physics 101. In the real world, the earth isn't flat.

Well I assume the OP is posing a Physics 101 question, because this is the exact type of question that would appear in Physics 101. But regardless, you said it yourself. The real world isn't flat. So why bother to account for curvature of the earth when you have hills and valleys much larger than 2.8 inches to contend with?

 

[Armitage]

Originally posted by: Triumph

Originally posted by: 91TTZ

Originally posted by: sonoma1993
i took 2 year of physics class. it funny reading half the answer in this post that are wrong. In a perfect enviroment, both bullets will hit the ground at the same time. But in the real world, the time diffrence will probably be just hundreds or thousands of a second when both bullets hit the ground. Like someone said earlier, gravity is pushing down on both bullet at 9.81m/s.

Read the whole thread, and read a few pages back where we solved this mathematically. The curvature of the Earth will add a couple inches to the shot bullet's fall. The dropped bullet will need to fall 4 feet, while the shot bullet will need to fall 4 feet and a couple inches due to the amount of Earth curvature under the bullet which just traveled horizontally a few thousand feet.

So what, no elementary physics book in the world is going to ask a Physics 101 student to incorportate the curvature of the earth. The answer is that they will land at the same time.

shrug - with those assumptions it's not an interesting question. Anybody with even a basic understanding of physics should get it, and the thread would have ended with the 2nd post.

Granted, that appears to exclude the majority of ATOT. But the more accurate answer is far more interesting.

As to actually demonstrating it - I suspect you could over a large body of water on a very calm day.

 

[oogabooga]

heh it's kinda funny cause it's almost like everyone agrees (with small exception) : they just disagree on what to discount/assume.

I think the short answer is that they will land at the 'same' time.
the long answer is no they wont.