Gunfight: Top of a speeding train.

Site Notices

[ARCHIVED THREAD] - Gunfight: Top of a speeding train. (Page 1 of 2)

Posted: 1/8/2006 10:12:58 AM EDT

Scenario, two guys, with handguns, on top of a train, moving at roughly ~150mph. Both men have similar handguns, same caliber, same load, bullet size and barrel length, effectively the guns are the same.

They both fire at each other at exactly the same moment, both are completely accurate shots.

Lets say that there is no friction due to air resistance (it's a train in space or something).

I say they both get hit at the same time. What do you think?

Posted: 1/8/2006 10:14:43 AM EDT

[#1]

same time. Its the frame of reference thing

Posted: 1/8/2006 10:15:03 AM EDT

[#2]

you're right

Posted: 1/8/2006 10:15:38 AM EDT

[#3]

Yes they both get hit at the same time. The bullets are each already traveling at 150mph before they leave the chamber, and with no friction/air resistance, it makes no difference. It would just be like if they were standing on a still train.

Posted: 1/8/2006 10:25:16 AM EDT

[#4]

The train pulls into the Chicago train station at 1:45pm but the two men get arrested for
not having their FOID cards.

I was really good at these in grade school.....NOT!

GM

Posted: 1/8/2006 10:26:31 AM EDT

[#5]

dupe, no an airplane cannot take of from a conveyer belt.

oh wait, nevermind.

Posted: 1/8/2006 10:26:40 AM EDT

[#6]

Can a Airplane takeoff off a conveyor belt?

EDIT beat by 9 secs

Posted: 1/8/2006 10:29:01 AM EDT

[#7]

Is the airplane moving on the conveyor belt or staying still?

Posted: 1/8/2006 10:29:44 AM EDT

[#8]

They would get shot at the same time unless the train accelerated or turned after the bullets left the gun.

Posted: 1/8/2006 10:32:07 AM EDT

[#9]

Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

Posted: 1/8/2006 10:34:57 AM EDT

[#10]

Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

The earth is rotating at 1k mph. does that mean firing west makes the bullet go faster in relation to the planet?

Posted: 1/8/2006 10:40:25 AM EDT

[#11]

Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

edited because im a FUCKING DUMBASS and theredhorseman is right.

dont drink and post people.

coke and jack is good.

Posted: 1/8/2006 10:45:21 AM EDT

[#12]

Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

The earth is rotating at 1k mph. does that mean firing west makes the bullet go faster in relation to the planet?

Let me rephrase my statement above: the bullets will be the same speed in relation to the earth, but the bullet fired rearward will close the distance to the target 150 mph faster than the bullet fired forward because the target is traveling 150 mph toward the bullet.

Posted: 1/8/2006 10:47:15 AM EDT

[#13]

Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

the bullet wont be faster, the target will just be moving at the bullet.

think of it like this. two men are standing in an open field, 50 yards apart. both aim guns at each other. one begins running at the other as fast as he can. they both fire when they reach 25 yards apart.

the one running would be hit first, even if only by miliseconds, because his forward movement put him closer to the bullet after it fired. since the bullet had to travel less then 25 yards, and the other will have to travel 25 yards, and assuming both projectiles have the same velocity, the runner will be hit before the one standing.

now we transpose this situation onto the train scenario. instead of one man running, one man is being pulled into the bullet by the speed of the train. if they were both 25 yards away, one bullet would have to travel 25 yards, while the other would have to travel less then 25 yards, because the target is being pulled towards the bullet.

Posted: 1/8/2006 10:48:05 AM EDT

[#14]

you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

Posted: 1/8/2006 10:55:13 AM EDT

[#15]

Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

Posted: 1/8/2006 10:58:21 AM EDT

[#16]

everything is moving, the velocity at which they are moving is irrelevant.

if two people were standing on main street, anytown, USA, where there happened to be a total lack of atmosphere for some stupid reason, and they shot at the exact same time with identical rounds from identical pistols, would one get hit before the other? by your reasoning they would as they are moving since the planet is moving.

Posted: 1/8/2006 10:59:10 AM EDT

[#17]

To the guys on the train, it would appear just as it would be on the ground. I think.

Because everything on the train has an equal vector already, so it's irrelevant. I think.

Been a long time since I took University Physics.

Posted: 1/8/2006 11:00:13 AM EDT

[#18]

Quoted:
Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

The earth is rotating at 1k mph. does that mean firing west makes the bullet go faster in relation to the planet?

Let me rephrase my statement above: the bullets will be the same speed in relation to the earth, but the bullet fired rearward will close the distance to the target 150 mph faster than the bullet fired forward because the target is traveling 150 mph toward the bullet.

Everything on top of the train is travelling in the same direction at the same speed prior to trigger pull. They will both reach their targets at the same time.

Posted: 1/8/2006 11:00:29 AM EDT

[#19]

Quoted:
Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

I'd go easy on the "dumbass," since if you just looked this up, or paid better attention in physics you'd realize he is right

. Maybe you didn't read the problem correctly. The one thing it asked is who gets shot first. Not how fast shit was going.

Posted: 1/8/2006 11:04:52 AM EDT

[#20]

Quoted:
everything is moving, the velocity at which they are moving is irrelevant.

if two people were standing on main street, anytown, USA, where there happened to be a total lack of atmosphere for some stupid reason, and they shot at the exact same time with identical rounds from identical pistols, would one get hit before the other? by your reasoning they would as they are moving since the planet is moving.

Back to the original problem: Imagine this: you and I are having a rock war on top of a train, where do want to be front or back of a 150 mph train?

Posted: 1/8/2006 11:07:23 AM EDT

[#21]

considering that there is no atmospheric drag to contend with, it wouldnt matter

Posted: 1/8/2006 11:07:57 AM EDT

[#22]

In an airless vacuum sound will not travel. Rock war impossible.

Posted: 1/8/2006 11:10:18 AM EDT

[#23]

So whens Old_Painless gonna do the train of truth?

Posted: 1/8/2006 11:11:16 AM EDT

[#24]

Quoted:
So whens Old_Painless gonna do the train of truth?

soon as I get done building a big enough vacuum chamber to house the train

Posted: 1/8/2006 11:11:31 AM EDT

[#25]

Quoted:
Quoted:
everything is moving, the velocity at which they are moving is irrelevant.

if two people were standing on main street, anytown, USA, where there happened to be a total lack of atmosphere for some stupid reason, and they shot at the exact same time with identical rounds from identical pistols, would one get hit before the other? by your reasoning they would as they are moving since the planet is moving.

Back to the original problem: Imagine this: you and I are having a rock war on top of a train, where do want to be front or back of a 150 mph train?

So lets take something less violent like baseball and apply your flawed physics. If I can throw 70mph and the train is going 70mph, I throw back to front - you have to catch a 140 mph fastball (ie rip your fuckin hand off). The other way you could kick back and drink beer because the ball would never get to you.

Is your theory starting to sound wrong yet?

Google dude.... google

Posted: 1/8/2006 11:12:31 AM EDT

[#26]

Quoted:
Quoted:
Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

I'd go easy on the "dumbass," since if you just looked this up, or paid better attention in physics you'd realize he is right . Maybe you didn't read the problem correctly. The one thing it asked is who gets shot first. Not how fast shit was going.

You guys just dont get it , 1 bullet is travelling 1100 fps toward atarget that is retreating at 150 mph. The other bullet is travelling 1100 fps toward a taget that is advancing at 150 mph.

Posted: 1/8/2006 11:13:46 AM EDT

[#27]

I blame this thread on the public school system.

This is a linear change in reference frame folks! Simple addition!

Reference frame A: holding still

Man A - velocity 0 mph
Man B - velocity 0 mph
Bullet A - velocity 800 mph (puny 9mm)
Bullet B - velocity (-800) mph (same)

Difference in Man A and Bullet B - 800 mph
Difference in Man B and Bullet A - 800 mph

Both die at the same time.

Reference frame B: on train at 150 mph
Man A - 150 mph
Man B - 150 mph
Bullet A - 950 mph
Bullet B (-650) mph

Difference in Man A and Bullet B - 800 mph
Difference in Man B and Bullet A - 800 mph

Both die at the same time.

Please close this thread.

Posted: 1/8/2006 11:13:57 AM EDT

[#28]

Quoted:
Quoted:
So whens Old_Painless gonna do the train of truth?

soon as I get done building a big enough vacuum chamber to house the train

k

so like a couple months?

Posted: 1/8/2006 11:16:40 AM EDT

[#29]

you dont understand inertia. the lead bullet has to accellerate through the 150mph that it is already travelling, negating the 150mph that the target is travelling at. the rear bullet has the "extra" 150mph for free and thus negates the 150mph that its target is running away with.

hows that for mixed frame of reference confusion?

Posted: 1/8/2006 11:17:01 AM EDT

[#30]

Quoted:
Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

But aren't the rounds also moving at the same time in the same direction?

Posted: 1/8/2006 11:17:59 AM EDT

[#31]

Same time... both handguns are firing within the same system. - Kool-Aid (LCA ts1337)

Posted: 1/8/2006 11:19:03 AM EDT

[#32]

You guys just dont get it , 1 bullet is travelling 1100 fps toward atarget that is retreating at 150 mph. The other bullet is travelling 1100 fps toward a taget that is advancing at 150 mph.

Okay kids... do this

Google "frame of reference" and "how to accept it when you are wrong"

or just look a few posts above for a perfect mathamatical explaination

Posted: 1/8/2006 11:21:23 AM EDT

[#33]

Quoted:
Let me rephrase my statement above: the bullets will be the same speed in relation to the earth, but the bullet fired rearward will close the distance to the target 150 mph faster than the bullet fired forward because the target is traveling 150 mph toward the bullet.

Holy crap. Take a physics course. The bullets will hit at the same time.

zonan
B.S. physics, summa cum laude

Posted: 1/8/2006 11:21:58 AM EDT

[#34]

Quoted:
Quoted:
Quoted:
Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

I'd go easy on the "dumbass," since if you just looked this up, or paid better attention in physics you'd realize he is right . Maybe you didn't read the problem correctly. The one thing it asked is who gets shot first. Not how fast shit was going.

You guys just dont get it , 1 bullet is travelling 1100 fps toward atarget that is retreating at 150 mph. The other bullet is travelling 1100 fps toward a taget that is advancing at 150 mph.

Jesus Christ! Quit mixing the frames of reference. Your statement is correct in its atoms but assembled ass-backwards.

Yes! One guy is travelling 150mph. RELATIVE TO THE GROUND. A bullet is travelling towards him at 1100 fps. RELATIVE TO THE TRAIN. If you calculate the problem entirely from the FRAME OF THE GROUND one guy is moving 150, the other is 150, and the two bullets are travelling 1100fps+/-150mph. Both get hit at the same time. Or measure from the FRAME OF THE TRAIN. Both guys are standing still on the train and both bullets move at 1100 fps relative to the train. Both get hit at the same time.

If you mix your reference frames you can get all kind of crazy answers.

Think about it: if you are right why do they put guns on supersonic jet fighters? If the plane is moving as fast as the bullet then won't it just get stuck in the barrel? And if you say that plane guns have to use some kind of super high velocity round to overcome this I am going to fly through this internet and shove the truth up your ignorant ass!

Posted: 1/8/2006 11:23:37 AM EDT

[#35]

Quoted:
considering that there is no atmospheric drag to contend with, it wouldnt matter

CORRECT !

Posted: 1/8/2006 11:30:19 AM EDT

[#36]

you should hear the argument i had with my roommate over geometry and a pool shot i missed this morning. he is the one that just pointed out my flawed logic in this post.

sometimes its funny when you get your ass handed to you. this is in refernce to me and not inatree.

Posted: 1/8/2006 11:43:04 AM EDT

[#37]

Quoted:
Quoted:
Quoted:
Quoted:
Quoted:
you people are fucking stupid, what does target velocity relative to the earth have to do with this at all? there is no drag in this problem, the targets are firing identical rounds with equal velocity at the exact same moment. the speed at which they are travelling is irrelevant as they are both going the same speed.

After firing the rounds the targets are still moving, dumbass!

I'd go easy on the "dumbass," since if you just looked this up, or paid better attention in physics you'd realize he is right . Maybe you didn't read the problem correctly. The one thing it asked is who gets shot first. Not how fast shit was going.

You guys just dont get it , 1 bullet is travelling 1100 fps toward atarget that is retreating at 150 mph. The other bullet is travelling 1100 fps toward a taget that is advancing at 150 mph.

Jesus Christ! Quit mixing the frames of reference. Your statement is correct in its atoms but assembled ass-backwards.

Yes! One guy is travelling 150mph. RELATIVE TO THE GROUND. A bullet is travelling towards him at 1100 fps. RELATIVE TO THE TRAIN. If you calculate the problem entirely from the FRAME OF THE GROUND one guy is moving 150, the other is 150, and the two bullets are travelling 1100fps+/-150mph. Both get hit at the same time. Or measure from the FRAME OF THE TRAIN. Both guys are standing still on the train and both bullets move at 1100 fps relative to the train. Both get hit at the same time.

If you mix your reference frames you can get all kind of crazy answers.

Think about it: if you are right why do they put guns on supersonic jet fighters? If the plane is moving as fast as the bullet then won't it just get stuck in the barrel? And if you say that plane guns have to use some kind of super high velocity round to overcome this I am going to fly through this internet and shove the truth up your ignorant ass!

I think you just did it

Its starting to make sense now although my short attention span has moved on so will never fully comprehend

Posted: 1/8/2006 11:44:40 AM EDT

[#38]

OK, you morons who probably went to public school, here are the facts:

If two people were on a moving train, one facing forwards and one facing backwards, and they fired the exact same kind of round from the exact same kind of gun, each bullet would hit the other with exactly the same speed!

Don't give me that crap about "Oh, but the person facing forwards will have the speed of the train added to his bullet, so it will be traveling faster!" That is ONLY true if he's shooting at someone on the ground!

Let's say the train is traveling 50 mph. The bullets travel 600mph. If someone shoots frontwards at someone on the ground, the person will get hit with a bullet traveling 650mph. But if he shoots at someone who is on the train, he will get hit with a bullet traveling 600mph. Likewise, if the person shooting backwards hits someone on the ground, his bullet will hit the person on the ground at 550mph, but if he shoots someone on the train, it will hit the person at 600mph.

Repeat after me: In physics, everything is relative. Everything on the train is a closed system. If you took that system and put it on a spacecraft, or on solid earth, it would work exactly the same way. Only if you go outside that system, such as shooting at someone on the ground from the train, is there any difference.

It would not matter if you were the person facing toward the front or rear of the moving train, if you are both moving with the train, you are going to get hit just as hard either way!

Posted: 1/8/2006 11:47:50 AM EDT

[#39]

hey there bub, I went to public school and I got it right.

Posted: 1/8/2006 11:48:13 AM EDT

[#40]

Quoted:
Think about it: if you are right why do they put guns on supersonic jet fighters? If the plane is moving as fast as the bullet then won't it just get stuck in the barrel? And if you say that plane guns have to use some kind of super high velocity round to overcome this I am going to fly through this internet and shove the truth up your ignorant ass!

Yeah, and they need to carry two guns, one supergun for shooting frontwards, and one extremely weak gun for shooting backwards!

Posted: 1/8/2006 11:50:54 AM EDT

[#41]

Quoted:
hey there bub, I went to public school and I got it right.

It's like sports teams for some people. I'll plug for homeschooling and make fun of the opposition.

Posted: 1/8/2006 12:13:22 PM EDT

[#42]

Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

Yep.
The bullet from the front will travel at it's speed + the speed of the guy in back who's coming toward it.
The bullet fromt the back will travel at it's speed - the speed of the guy in front who is moving away from the bullet.

Posted: 1/8/2006 12:14:52 PM EDT

[#43]

Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

Yep.
The bullet from the front will travel at it's speed + the speed of the guy in back who's coming toward it.
The bullet fromt the back will travel at it's speed - the speed of the guy in front who is moving away from the bullet.

did you bother reading?

Posted: 1/8/2006 12:18:11 PM EDT

[#44]

Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

Yep.
The bullet from the front will travel at it's speed + the speed of the guy in back who's coming toward it.
The bullet fromt the back will travel at it's speed - the speed of the guy in front who is moving away from the bullet.

Frame of reference, dude. This is a closed system. Put this system anywhere and the results would be the same. If the train were not moving, things would happen exactly the same as if the train was traveling at any speed, taking air resistance out of account.

Posted: 1/8/2006 12:18:16 PM EDT

[#45]

Quoted:
Quoted:
Wrong, While it is true that the bullet fired in the direction of the trains travel will uneffected be the trains speed, The bullet travelling rearward will be the faster of the two bullets.

Yep.
The bullet from the front will travel at it's speed + the speed of the guy in back who's coming toward it.
The bullet fromt the back will travel at it's speed - the speed of the guy in front who is moving away from the bullet.

No dude , dont follow me. Ill get you killed on top of a train.

Posted: 1/8/2006 12:24:01 PM EDT

[#46]

I say the round hits the mirror and the paranoid guy shooting at his mirror image gets freaked out and falls off the train.

Posted: 1/8/2006 12:27:24 PM EDT

[#47]

OK, here's another way to think about it. Of course, to understand it, you WILL have to actually think.

The train is moving at 150 mph. But in relation to what? Why do we say that the train is moving? Because we are comparing its motion to the ground. In relation to the ground, the train is moving at 150 mph. But in relation to itself, it is not moving, and the ground is moving at 150 mph the opposite direction. Both understandings are just as valid, but since we live on the ground we compare the motion of objects to the ground, so we do not say that the ground is moving at 150 mph. But you could.

If you are on a moving sidewalk that is traveling at 2 mph and you walk down it at 2mph, are you traveling 2mph or 4mph? Well, actually both. Compared to the sidewalk you are traveling 2mph, but compared to the surrounding environment you are traveling 4mph. But if you take yourself as the frame of reference, you are not moving, and the sidewalk is moving backwards at 2mph and the surrounding environment is traveling backwards at 4mph.

With this in mind, we can simplify the original problem by saying that the train is not moving, but the surrounding environment is moving backwards at 150mph. Now, if these two men were standing on this stationary train and fired at each other with the exact same gun and round, would one bullet go faster than the other? No.

Posted: 1/8/2006 12:33:48 PM EDT

[#48]

Basic vector physics… All direct forces caused by the motion of the train cancel each other out so…

In a vacuum they get hit at EXACTLY the same instant.

or

If no vacuum the man in the back gets hit first due to the rearward relative wind speed forces induced by the train moving through air that is not moving.

The speed of the train has NO direct effect on bullet impact BECAUSE the forces effect each shooter in EXACTLY the same way…

Meaning they are not moving AT ALL relative to each other.

Posted: 1/8/2006 12:35:48 PM EDT

[#49]

Quoted:
Basic vector physics… All direct forces caused by the motion of the train cancel each other out so…

Might have to explain "vector."

A "vector" is the measure of an object's speed and direction.

Posted: 1/8/2006 12:44:16 PM EDT

[#50]

That's why a fly can fly around in the space in your car while you're driving at 60 MPH, but otherwise can not fly at 60 MPH in the middle of the woods.

[ARCHIVED THREAD] - Gunfight: Top of a speeding train. (Page 1 of 2)

General » General Discussion

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us