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Posted: 5/18/2015 8:57:48 AM EST
[#1]
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Ah, but consider firing a the same gun from inside the plane facing rearward. Is would still appear to travel at 2000fps right? That's because the plane is traveling at 2000fps, while the bullet remains static. Correct? Quote HistoryQuoted:
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So according to physics, if my plane is flying 2000fps and my bullet is fired rearward at 2000fps, the bullet would just remain where it left the barrel, and begin falling straight down??? Yes. An Aggie said it! /thread Ah, but consider firing a the same gun from inside the plane facing rearward. Is would still appear to travel at 2000fps right? That's because the plane is traveling at 2000fps, while the bullet remains static. Correct? while the bullet is static, you would be traveling away from it at 2000fps and anything is its path inside the plane would be traveling towards it at 2000fps. |
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Posted: 5/18/2015 9:28:41 AM EST
[#2]
I'm guessing momentum would be the critical factor at play here. The projectile's initial velocity would equal the sum of it's ballistic property or charge and the jet's speed; I don't know how to word it and am just guessing. This sum will begin with a positive speed favoring the projectile, diminish rapidly to the point of equalizing, then further progress to negative. The jet, being self-propelled and able to maintain it's velocity (it's speed being the constant), will overtake and surpass the slowing projectile's speed due to the projectile's lack of ability to maintain it's speed (drag, momentum, not self-propelled).
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Posted: 5/18/2015 9:31:50 AM EST
[#3]
DT...
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Posted: 5/18/2015 9:52:42 AM EST
[#4]
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You're being optimistic. I tend to be pessimistic, concerning aviation. I've seen too much stupid shit (and that may or may not include some of my own past actions), to not expect things to eventually go bad. Virtually impossible just means it takes more circumstances to properly align, for that outcome to occur. Impossible just means nobody has yet seen the combination of circumstances required for that outcome to occur. Quote HistoryQuoted:
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Could the aircraft shoot itself down with its own bullet?- not impossible by so unlikely as to be virtually impossible. For this to happen the aircraft would have to follow the the parabolic trajectory of the bullet exactly and effectively fly into the bullet and the aircraft caught up with the bullet. Depending on the closure speed the likely outcome even if this could be achieved would be the bullet bouncing off the aircraft or perhaps causing minor damage (unless it went into an engine intake I suppose). The Grumman F11F that shot itself down during flight testing, scored multiple hits on itself. The engineers working on that program probably thought it was impossible, too. Which is why I didn't say it was impossible.  I said it was virtually impossible. I actually described how it could happen.
You're being optimistic. I tend to be pessimistic, concerning aviation. I've seen too much stupid shit (and that may or may not include some of my own past actions), to not expect things to eventually go bad. Virtually impossible just means it takes more circumstances to properly align, for that outcome to occur. Impossible just means nobody has yet seen the combination of circumstances required for that outcome to occur. I think we are both saying the same thing here to be honest. Like I said - It's not impossible. 
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Posted: 5/18/2015 9:55:35 AM EST
[#5]
Quote HistoryQuoted: An Aggie said it! /thread Quote HistoryQuoted: Quoted: Quoted: So according to physics, if my plane is flying 2000fps and my bullet is fired rearward at 2000fps, the bullet would just remain where it left the barrel, and begin falling straight down??? Yes. An Aggie said it! /thread Just ensuring leatherface get's a taste of his crow. |
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Posted: 5/18/2015 10:04:49 AM EST
[#6]
Quote HistoryQuoted: This isn't correct. Classical mechanics don't work that way. Quote HistoryQuoted: Quoted: Quoted: Thou shalt not add thy velocity to the speed of light. Same principle applies here. Newtonian physics allows to the addition of velocities with the proviso that even in a pure vacuum, there is a minute deficit to the addition of velocity, which increases as the object firing the projectile increases it's own velocity and becoming significant as relativistic velocities are achieved. This isn't correct. Classical mechanics don't work that way. |
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Posted: 5/18/2015 10:07:46 AM EST
[#7]
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Does that mean if you put a flash light on the front of an aircraft going at Mach 4, that the light coming out from the front of the flash light will be going at the speed of light+Mach 4? ...effectively FASTER than the speed of light? Quote HistoryQuoted:
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Since the bullets are stationary relative to the motion of the aircraft they will be going the same speed of the aircraft. When they are fired you add the increased velocity to the now fired projectile.
Does that mean if you put a flash light on the front of an aircraft going at Mach 4, that the light coming out from the front of the flash light will be going at the speed of light+Mach 4? ...effectively FASTER than the speed of light? 
A bullet isn't traveling at c. Different issues. |
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Posted: 5/18/2015 10:09:24 AM EST
[#8]
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Lets use the A-10 as an example in this scenario. a Sub-sonic plane. The question was about a SUPERSONIC airplane. the round will leave the aircraft at the plane's airspeed + the muzzle velocity of the round. then aerodynamics come into play. what's the frontal area of the round, what's the coefficient of drag, etc, etc, it will rapidly slow down. |
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Posted: 5/18/2015 10:10:17 AM EST
[#9]
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I am in the front of a 747 with an open nose traveling at 570 MPH and I step out at a rate of 3 MPH, how fast am I traveling? How do I even overcome the blast of a 570 MPH wind bearing down on me? Quote HistoryQuoted:
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You are in the back of a 747 that is travelling at 570 mph, and you start to walk at a rate of 3 mph to the front of the plane. How fast are you travelling? I am in the front of a 747 with an open nose traveling at 570 MPH and I step out at a rate of 3 MPH, how fast am I traveling? How do I even overcome the blast of a 570 MPH wind bearing down on me? the wing or the horizontal stabilizer bisects you and the question is moot. |
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Posted: 5/18/2015 10:11:00 AM EST
[#10]
Quote HistoryQuoted: The projectile sitting in the chamber of the gun is motionless in relation to the chamber, barrel, etc. If the muzzle velocity of the projectile is 2,800 fps, the muzzle velocity is 2,800 fps regardless of the aircraft velocity. Show me an equation that demonstrates a .50 cal projectile, or any other, gains an additional 2,000 fps by being fired from an aircraft traveling at such speed. Relative to the ground, a the muzzle velocity will be 4,800 fps. Relative to the aircraft, the barrel, and the chamber, the muzzle velocity will be 2800 fps. Or are you suggesting that relative to the ground, the muzzle velocity would only be 800 fps? |
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Posted: 5/18/2015 10:15:29 AM EST
[#11]
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The chamber and barrel are moving at 2000 fps. Relative to the ground, a the muzzle velocity will be 4,800 fps. Relative to the aircraft, the barrel, and the chamber, the muzzle velocity will be 2800 fps. Or are you suggesting that relative to the ground, the muzzle velocity would only be 800 fps? Quote HistoryQuoted:
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The projectile sitting in the chamber of the gun is motionless in relation to the chamber, barrel, etc. If the muzzle velocity of the projectile is 2,800 fps, the muzzle velocity is 2,800 fps regardless of the aircraft velocity. Show me an equation that demonstrates a .50 cal projectile, or any other, gains an additional 2,000 fps by being fired from an aircraft traveling at such speed. Relative to the ground, a the muzzle velocity will be 4,800 fps. Relative to the aircraft, the barrel, and the chamber, the muzzle velocity will be 2800 fps. Or are you suggesting that relative to the ground, the muzzle velocity would only be 800 fps? So if a passing car, going 80, throws a 10 mph beer bottle at your dumb ass, will it hit you going 10 or 90? |
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Posted: 5/18/2015 10:24:09 AM EST
[#12]
Quote HistoryQuoted: It would seem that if the conditions the OP postulates obtain then it would be a well understood phenomenon, especially by the worlds various air forces and fighter pilots. It's simply not how it works. A projectile that has a charge giving it a mv of x when fired from a barrel on the ground doesn't exit a barrel at x*2 when fired from a moving platform. Quote HistoryQuoted: Quoted: Quoted: Thou shalt not add thy velocity to the speed of light. Same principle applies here. It would seem that if the conditions the OP postulates obtain then it would be a well understood phenomenon, especially by the worlds various air forces and fighter pilots. It's simply not how it works. A projectile that has a charge giving it a mv of x when fired from a barrel on the ground doesn't exit a barrel at x*2 when fired from a moving platform. Muzzle velocity relative to the aircraft is the same. Muzzle velocity relative to the ground is air speed plus muzzle velocity. |
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Posted: 5/18/2015 10:27:23 AM EST
[#13]
Quote HistoryQuoted: Frame of reference. Muzzle velocity relative to the aircraft is the same. Muzzle velocity relative to the ground is air speed plus muzzle velocity. Quote HistoryQuoted: Quoted: Quoted: Quoted: Thou shalt not add thy velocity to the speed of light. Same principle applies here. It would seem that if the conditions the OP postulates obtain then it would be a well understood phenomenon, especially by the worlds various air forces and fighter pilots. It's simply not how it works. A projectile that has a charge giving it a mv of x when fired from a barrel on the ground doesn't exit a barrel at x*2 when fired from a moving platform. Muzzle velocity relative to the aircraft is the same. Muzzle velocity relative to the ground is air speed plus muzzle velocity. |
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Posted: 5/18/2015 10:43:17 AM EST
[#14]
Quote HistoryQuoted: I AM pretty drunk!  But I'm also right. I think. Quote HistoryQuoted: Quoted: Quoted: Quoted: Quoted: So an observer from the ground holding a radar gun would record the projectile having a muzzle velocity of x (2,800 fps, let's say) + y (velocity of the aircraft). So that radar would record a muzzle velocity of 4,800 fps? I don't think so. Your avatar is VERY fitting. It is 4800fps, sherlock. No, it is not 4,800 fps. eta.. how the fuck would ground crews ever be able to regulate the guns if they had to take into account the varying speed of the aircraft? Even at 400 mph that would create problems. JESUS FUCKING CHRIST. REALLY? REALLLLLLLLLY DOOD? I'm embarrassed for you. I AM pretty drunk! But I'm also right. I think. You can't learn because you already know you are right. Several posters are framing the description correctly. They state the velocities of the projectiles with reference to the ground and the gun mounted to the aircraft. |
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Posted: 5/18/2015 10:46:48 AM EST
[#15]
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It will go at the speed of the projectile plus the speed of the plane. lol this. cool thing is a super sonic plane shooting out of the rear the bullets are barely moving. Shoots self down |
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Posted: 5/18/2015 10:49:45 AM EST
[#16]
Speed is relevant to the observers.
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Posted: 5/18/2015 10:54:29 AM EST
[#17]
Quote HistoryQuoted: So if a passing car, going 80, throws a 10 mph beer bottle at your dumb ass, will it hit you going 10 or 90? Quote HistoryQuoted: Quoted: Quoted: The projectile sitting in the chamber of the gun is motionless in relation to the chamber, barrel, etc. If the muzzle velocity of the projectile is 2,800 fps, the muzzle velocity is 2,800 fps regardless of the aircraft velocity. Show me an equation that demonstrates a .50 cal projectile, or any other, gains an additional 2,000 fps by being fired from an aircraft traveling at such speed. Relative to the ground, a the muzzle velocity will be 4,800 fps. Relative to the aircraft, the barrel, and the chamber, the muzzle velocity will be 2800 fps. Or are you suggesting that relative to the ground, the muzzle velocity would only be 800 fps? So if a passing car, going 80, throws a 10 mph beer bottle at your dumb ass, will it hit you going 10 or 90? |
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Posted: 5/18/2015 10:57:07 AM EST
[#18]
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Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. |
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Posted: 5/18/2015 10:57:38 AM EST
[#19]
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are we going supersonic on a treadmill? This is the correct answer for GD. |
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Posted: 5/18/2015 11:00:30 AM EST
[#20]
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lol this. cool thing is a super sonic plane shooting out of the rear the bullets are barely moving. Shoots self down Quote HistoryQuoted:
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It will go at the speed of the projectile plus the speed of the plane. lol this. cool thing is a super sonic plane shooting out of the rear the bullets are barely moving. Shoots self down As per article... snip..."11 seconds later, flew through them as their flight paths met.." |
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Posted: 5/18/2015 11:00:38 AM EST
[#21]
Quote HistoryQuoted: Ground speed plus bullet velocity. Quote HistoryQuoted: Quoted: Frame of reference. Muzzle velocity relative to the aircraft is the same. Muzzle velocity relative to the ground is air speed plus muzzle velocity. |
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Posted: 5/18/2015 11:01:02 AM EST
[#22]
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Ground speed plus bullet velocity. Quote HistoryQuoted:
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Thou shalt not add thy velocity to the speed of light. Same principle applies here. It would seem that if the conditions the OP postulates obtain then it would be a well understood phenomenon, especially by the worlds various air forces and fighter pilots. It's simply not how it works. A projectile that has a charge giving it a mv of x when fired from a barrel on the ground doesn't exit a barrel at x*2 when fired from a moving platform. Muzzle velocity relative to the aircraft is the same. Muzzle velocity relative to the ground is air speed plus muzzle velocity. Minus air friction. |
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Posted: 5/18/2015 11:01:15 AM EST
[#23]
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Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. I think we can assume the air in the barrel is essentially static relative to the projectile. Relative air speed outside the barrel shouldn't effect the bullet until it has cleared the barrel. Hence "muzzle" velocity.
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Posted: 5/18/2015 11:09:36 AM EST
[#24]
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Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. You're injecting exterior ballistics to the problem which adds complexity to the actual bullet behavior after it leaves the muzzle. But, bullet velocity, relative to ground, will be the the sum of the velocities at the instant it leaves the muzzle. Then exterior ballistics come into play. Drag on the projectile is a function of velocity and its going much faster than the same projectile fired from a ground based gun so the drag is much greater. The beer bottle example- youre going to get hit by a beer bottle going 80 mph in x with a 10 mph y component. Net velocity would be about 80.6 mph. |
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Posted: 5/18/2015 11:09:37 AM EST
[#25]
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Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Correct! The drag coefficient increases drastically around the speed of sound and then drops off at higher speeds. 
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Serious question, then: In the vacuum of space, a space ship flying just under the speed light (c - 1,000fps; theoretically possible) fires its .50BMG. Will the bullet exiting the barrel exceed the speed of light by around 1,800 fps? Or, if the same space ship has headlights and is zooming along at the same c - 1,000fps, does the light from the headlights project through space at nearly twice the speed of light? "Teachers" told me for years that nothing can exceed the speed of light. I never believed them. Any enlightenment welcome. Your teachers were correct. Theory of special relativity |
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Posted: 5/18/2015 11:11:27 AM EST
[#26]
Whatever the velocity of the cannon is setting still. If a plane was fast enough It could hit the projectiles from its own gun.
Lets say you ar standing on a tower and fire a bullet traveling 3000FPS at the exact milisecond a Plane comes by traveling at 2400 miles per hour. The plane would be flying faster then the projectile and would over take it. |
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Posted: 5/18/2015 11:39:59 AM EST
[#27]
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Is there drag in a fighters gun barrel? Forget "Mach", I guess I shouldn't have used that term. Could an aircraft be flying at a speed where a bullet wouldn't have the ability to leave the barrel of its gun? I'm not being a smartass, I am just wondering. No. I don't believe so. I work with a bunch of people with Masters in Engineering, Aero and Astro. Bullets are already flying supersonic. And supersonic drag is lower than transsonic or infrasonic. |
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Posted: 5/18/2015 11:44:02 AM EST
[#28]
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Velocity of Plane (1100 fps) + Velocity of Bullet at muzzle (3000 fps)= 4100 fps (speed of bullet for one split second till aerodynamics take over). Immediately leaving the barrel the bullet will be going fast, but losing velocity as soon as it leaves the barrel. Since the plane has the power to keep it's speed the plane will catch the bullet eventually. So, yes a plane can shoot itself down if it comes into the path of it's own bullets. Ground observer will see bullet going 4100 fps and the plane will see it going 3000 fps. NO There is this thing called gravity. It is going to suck the bullet toward the ground. The plane has a thing called lift. In level flight the plane is not moving toward the center of the earth. The bullet is. BULLETS do no normally experience lift, despite what you may think. |
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Posted: 5/18/2015 11:49:38 AM EST
[#29]
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I am in the front of a 747 with an open nose traveling at 570 MPH and I step out at a rate of 3 MPH, how fast am I traveling? How do I even overcome the blast of a 570 MPH wind bearing down on me? Quote HistoryQuoted:
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You are in the back of a 747 that is travelling at 570 mph, and you start to walk at a rate of 3 mph to the front of the plane. How fast are you travelling? I am in the front of a 747 with an open nose traveling at 570 MPH and I step out at a rate of 3 MPH, how fast am I traveling? How do I even overcome the blast of a 570 MPH wind bearing down on me? This isn't a good scenario to investigate your first question. There is a lot more in play. Forget it, unless you want to sidetrack the whole discussion. Whoops, too late. |
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Posted: 5/18/2015 11:55:48 AM EST
[#30]
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Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. |
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Posted: 5/18/2015 12:29:17 PM EST
[#31]
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So the laws of physics change depending on if you are goingfforward or reverse? Interesting... Quote HistoryQuoted:
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This question that has been tickling my brain. I'm sure it never happens, but what if a fighter fired its gun at speeds above Mach? Would the projectiles be Mach plus their normal speed??? Would the projectiles just fall out of the barrel and keep pace with the plane? Could a plane shoot itself down? I have read that the B-58 had its rear firing cannon removed because it could fly faster than the projectiles it fired could leave the barrel. What say the collective GD mind? It will go as fast as any normal bullet would. In the case of the 20mm Vulcan, wiki says 3,450 feet per second. It isn't 3450 + the speed of the plane. You initially get the speed of the plane and then the speed of the bullet , but the bullet starts to slow down the moment it leave the barrel - and especially if the plane speeds up, it can hit the plane. By comparison, Mach 2 is about 2200 feet per second. But yes, if the plane is going faster than the bullet, then the bullet will hit the plane. The bullet is only accelerating until it reaches the end of the barrel. Here is an account of a pilot who shot his own plane in a dive in the 50s. His bullets I think were slower than the modern Vulcan, though. http://www.check-six.com/Crash_Sites/Tiger138260.htm Here is a Mythbusters video showing what would happen if you shot a bullet out of a plane backwards and were going as fast as the bullet. The bullet would leave the barrel because of the pressure, but then this happens:  http://www.youtube.com/watch?v=BLuI118nhzcyour own video shows you to be wrong  The video shows what happens if you shot it backwards - not forwards. In that case IIRC the truck shot the ball at 60mph while it traveled at 60mph. The link explains what happens when you shoot a bullet forwards at high speeds and shows how it is possible to shoot yourself down. So the laws of physics change depending on if you are goingfforward or reverse? Interesting... Well in order to reply, I guess you will have to explain what you think would happen and why. If you read my link it gives you a real world example of what can happen when things go wrong. |
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Posted: 5/18/2015 12:29:21 PM EST
[#32]
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I think we are both saying the same thing here to be honest. Like I said - It's not impossible. Quote HistoryQuoted:
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Could the aircraft shoot itself down with its own bullet?- not impossible by so unlikely as to be virtually impossible. For this to happen the aircraft would have to follow the the parabolic trajectory of the bullet exactly and effectively fly into the bullet and the aircraft caught up with the bullet. Depending on the closure speed the likely outcome even if this could be achieved would be the bullet bouncing off the aircraft or perhaps causing minor damage (unless it went into an engine intake I suppose). The Grumman F11F that shot itself down during flight testing, scored multiple hits on itself. The engineers working on that program probably thought it was impossible, too. Which is why I didn't say it was impossible. I said it was virtually impossible. I actually described how it could happen.
You're being optimistic. I tend to be pessimistic, concerning aviation. I've seen too much stupid shit (and that may or may not include some of my own past actions), to not expect things to eventually go bad. Virtually impossible just means it takes more circumstances to properly align, for that outcome to occur. Impossible just means nobody has yet seen the combination of circumstances required for that outcome to occur. I think we are both saying the same thing here to be honest. Like I said - It's not impossible. No, this is a General Discussion thread involving planes and physics. There can be no agreement.
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Posted: 5/18/2015 12:34:42 PM EST
[#33]
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The projectile sitting in the chamber of the gun is motionless in relation to the chamber, barrel, etc. If the muzzle velocity of the projectile is 2,800 fps, the muzzle velocity is 2,800 fps regardless of the aircraft velocity. Show me an equation that demonstrates a .50 cal projectile, or any other, gains an additional 2,000 fps by being fired from an aircraft traveling at such speed. Yep. "Reading is for fags!" Threads like these explain the derp that some post in other threads....and the number of people that believe in magic here. lol |
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Posted: 5/18/2015 12:38:57 PM EST
[#34]
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Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. You are wrong. As shown above as well, drag isn't significantly higher above the transsonic region with increased velocity. Therefore, the drag force experience by the projective at say mach 1.5 may be HIGHER than it would be at mach 2.5. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. You are wrong. As shown above as well, drag isn't significantly higher above the transsonic region with increased velocity. Therefore, the drag force experience by the projective at say mach 1.5 may be HIGHER than it would be at mach 2.5. The in-flight muzzle velocity is going to be slightly lower than what you'd see in a ground test because of the initial stagnation pressure in the barrel. The difference is small, maybe a tenth of a percent when you work out the math. The drop and maybe drift are also going to be very strong functions of aircraft speed. The drag force is a function of V2, so if you double the speed of the projectile, you have roughly quadrupled the drag force - the small variations in drag coefficient at those velocities is not that significant. And drift is weird, because I think a moving aircraft means you effectively have a variable twist - but I haven't fully thought this out. |
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Posted: 5/18/2015 12:40:26 PM EST
[#35]
Did we already talk treadmills? Not reading 5 pages of this...
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Posted: 5/18/2015 12:42:57 PM EST
[#36]
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Does that mean if you put a flash light on the front of an aircraft going at Mach 4, that the light coming out from the front of the flash light will be going at the speed of light+Mach 4? ...effectively FASTER than the speed of light? Quote HistoryQuoted:
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Since the bullets are stationary relative to the motion of the aircraft they will be going the same speed of the aircraft. When they are fired you add the increased velocity to the now fired projectile.
Does that mean if you put a flash light on the front of an aircraft going at Mach 4, that the light coming out from the front of the flash light will be going at the speed of light+Mach 4? ...effectively FASTER than the speed of light? No. At those kinds of velocities, classical physics models break down and you have to use general relativity. Don't ask me to explain it, I know what some of the effects of relativity are at relativistic speeds, but it can bend your brain. Suffice to say, the universe kind of sort of 'corrects' for the scenario you're talking about with an effect called time dilation. If you are interested, the wikipedia entry is a good basic starting place: http://en.wikipedia.org/wiki/Time_dilation |
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Posted: 5/18/2015 1:03:32 PM EST
[#37]
At 0.0000044c, I think we can limit this discussion to Newtonian mechanics.
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Posted: 5/18/2015 1:12:32 PM EST
[#38]
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Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. You are wrong. As shown above as well, drag isn't significantly higher above the transsonic region with increased velocity. Therefore, the drag force experience by the projective at say mach 1.5 may be HIGHER than it would be at mach 2.5. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. You are wrong. As shown above as well, drag isn't significantly higher above the transsonic region with increased velocity. Therefore, the drag force experience by the projective at say mach 1.5 may be HIGHER than it would be at mach 2.5. Drag at mach 2.5 will be higher - much higher - than at mach 1.5. It is the coefficient that will be lower. |
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Posted: 5/18/2015 1:14:48 PM EST
[#39]
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It will go at the speed of the projectile plus the speed of the plane. Until wind resistance slows the projectile down, then the plane will run into it. 
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Posted: 5/18/2015 1:18:45 PM EST
[#40]
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No, this is a General Discussion thread involving planes and physics. There can be no agreement. Quote HistoryQuoted:
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Which is why I didn't say it was impossible. I said it was virtually impossible. I actually described how it could happen.
You're being optimistic. I tend to be pessimistic, concerning aviation. I've seen too much stupid shit (and that may or may not include some of my own past actions), to not expect things to eventually go bad. Virtually impossible just means it takes more circumstances to properly align, for that outcome to occur. Impossible just means nobody has yet seen the combination of circumstances required for that outcome to occur. I think we are both saying the same thing here to be honest. Like I said - It's not impossible. No, this is a General Discussion thread involving planes and physics. There can be no agreement. LOL'd
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Posted: 5/18/2015 1:19:15 PM EST
[#41]
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Well in order to reply, I guess you will have to explain what you think would happen and why. If you read my link it gives you a real world example of what can happen when things go wrong. you seem to be saying that the bullet fired forward will NOT have an increased ground speed caused by the speed of the aircraft. you seem to believe that the video of the ball falling out the end of the cannon firing behind the truck proves this. |
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Posted: 5/18/2015 1:23:14 PM EST
[#42]
Go drive down the road at 10MPH and drop a ball bearing out the window. the velocity of the car is not imparted on the thing you drop. The principal applies to connons being fired on a plane. If the plane s traveling faster then the projectiles at the muzzle, the bullets will simply exit the barrel and either hit the plane or fall away.
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Posted: 5/18/2015 1:55:39 PM EST
[#43]
Quote HistoryQuoted: Go drive down the road at 10MPH and drop a ball bearing out the window. the velocity of the car is not imparted on the thing you drop. The principal applies to connons being fired on a plane. If the plane s traveling faster then the projectiles at the muzzle, the bullets will simply exit the barrel and either hit the plane or fall away. You're either trolling or retarded. |
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Posted: 5/18/2015 2:18:18 PM EST
[#44]
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You're either trolling or retarded. Quote HistoryQuoted:
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Go drive down the road at 10MPH and drop a ball bearing out the window. the velocity of the car is not imparted on the thing you drop. The principal applies to connons being fired on a plane. If the plane s traveling faster then the projectiles at the muzzle, the bullets will simply exit the barrel and either hit the plane or fall away. You're either trolling or retarded. lol |
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Posted: 5/18/2015 2:21:00 PM EST
[#45]
THANK YOU! That is all I thought about lol
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Posted: 5/18/2015 2:21:41 PM EST
[#46]
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It will go at the speed of the projectile plus the speed of the plane. Briefly. Once it leaves the barrel, it will slow dramatically. In a test in the early supersonic era, a fighter shot itself down when it flew into the slowing projectiles at supersonic speed. TC |
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Posted: 5/18/2015 2:26:44 PM EST
[#47]
BBBBRRRRRRRPPPPPPPP!!
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Posted: 5/18/2015 2:29:46 PM EST
[#48]
I have nipples Focker. Can you milk me?
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Posted: 5/18/2015 2:34:57 PM EST
[#49]
It does make one wonder how waist gunners ever hit anything. Perhaps at the relatively slow speed of a bomber the bullet isnt greatly affected by the lateral drag? (I.e., the bullet has the velocity of the bomber, but it's sideways to the bullet., our bullet is travelling 2800 fps away from the plane but it also has a roughly 400 fps sideways component)
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Posted: 5/18/2015 2:36:10 PM EST
[#50]
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The in-flight muzzle velocity is going to be slightly lower than what you'd see in a ground test because of the initial stagnation pressure in the barrel. The difference is small, maybe a tenth of a percent when you work out the math. The drop and maybe drift are also going to be very strong functions of aircraft speed. The drag force is a function of V2, so if you double the speed of the projectile, you have roughly quadrupled the drag force - the small variations in drag coefficient at those velocities is not that significant. And drift is weird, because I think a moving aircraft means you effectively have a variable twist - but I haven't fully thought this out. Quote HistoryQuoted:
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Dang, all these answers and only two of them serious! So all you physics experts that think I am stupid, can you dumb it down just a LITTLE bit to explain what will happen? Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps Nope. You're ignoring air and other coefficients. Air friction is not linear with increased speed. Air is a coefficient? What other coefficients are you talking about here? We are talking about initial velocity here. What effect air has on the projective has nothing to do with the initial velocity. The drag force exerted by the air begins when the bullet exits the barrel, not before. You are wrong. As shown above as well, drag isn't significantly higher above the transsonic region with increased velocity. Therefore, the drag force experience by the projective at say mach 1.5 may be HIGHER than it would be at mach 2.5. The in-flight muzzle velocity is going to be slightly lower than what you'd see in a ground test because of the initial stagnation pressure in the barrel. The difference is small, maybe a tenth of a percent when you work out the math. The drop and maybe drift are also going to be very strong functions of aircraft speed. The drag force is a function of V2, so if you double the speed of the projectile, you have roughly quadrupled the drag force - the small variations in drag coefficient at those velocities is not that significant. And drift is weird, because I think a moving aircraft means you effectively have a variable twist - but I haven't fully thought this out. That may be true however most of you who THINK you have it figured out are also forgetting something very important. What altitude is this supersonic aircraft at? At sea level is vastly different than 35,000'. That will have a huge effect on the drag force experienced by the projective. And, no matter what anyone says, the bullets will start to drop away from the aircraft's line of travel as soon as they leave the barrel. They will accelerate towards the earth's center at 9.80655 m/s^2. The plane, assuming level flight, is not. You can't run into your own bullets unless you yourself are in a dive. |
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