User Panel
Posted: 5/17/2015 10:39:30 PM EDT
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 at the speed of the projectile plus the speed of the plane.
|
|
Velocity of aircraft + velocity of projectile
ETA: Damn...TWO seconds |
|
Initial muzzle velocity, plus the aircraft's forward velocity at the moment of firing, minus effects of atmospheric drag, acceleration of gravity taken into account.
|
|
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.
|
|
They can't, because the projectile will just hover in front of them until it slows enough that the plane hits it. The only reason they have cannons is because of government waste and corruption.
Posted Via AR15.Com Mobile |
|
|
Psh, ridiculous question.
Everyone knows fighters don't need cannons. |
|
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? |
|
There was a plane that actually shot itself down.
It fired its cannon level, and then entered a shallow dive, and managed to get under its own bullets, IIRC. |
|
|
|
|
Quoted:
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. View Quote 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? |
|
Quoted:
Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps View Quote View All Quotes View All Quotes Quoted:
Quoted:
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 But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? Quoted:
Lets use the A-10 as an example in this scenario. Let's not since the thread title had the word "supersonic" in it. |
|
Quoted:
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? View Quote The speed of sound is irrelevant. Let's perform a thought experiment. A plane is flying at 500 MPH = 733 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is travelling at 2,733 FPS. Now a plane is flying at 1,000 MPH (speed of sound is ca. 761 MPH) = 1,466 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is traveling at 1,466 = 2,000 FPS = 3,466 FPS. "Mach" is irrelevant. Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. |
|
African or european? Laden or unladen? These answers matter.
|
|
Thou shalt not add thy velocity to the speed of light.
Same principle applies here. |
|
Quoted:
But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? View Quote Drag acts upon the bullet and starts slowing it down as it travels in whatever trajectory that particular projectile travels at that velocity. Just like any other bullet. |
|
Quoted:
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? View Quote You are standing in the back of a bus going 100mph. You throw your fastest pitch (say 70 mph) at the windshield. Does the ball just drop to the ground? No. It moves towards the windshield at 70 mph. Since the bus is going 100 already the ball moves at 170 mph as seen from the outside of the bus. Or you are in an airliner going 500mph. You walk to the front at 1 1/2 mph to use the bathroom. Your velocity is 500 mph plus 1.5 mph = 501.5 mph. ETA: When the bullet hits the air at "hyper speed" it will experience more drag. |
|
Quoted:
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? View Quote View All Quotes View All Quotes Quoted:
Quoted:
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? Only if you're shooting wave-particle bullets. |
|
Quoted: But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? Let's not since the thread title had the word "supersonic" in it. View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: 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 But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? Quoted: Lets use the A-10 as an example in this scenario. Let's not since the thread title had the word "supersonic" in it. Inertia. The jet's speed is giving the bullets (and the cannon) energy in the form of inertia. So when the chemical reaction of the powder burning propels the projectile, it's starting with velocity-of-jet + energy imparted by the burning powder. Once the bullet leaves the barrel it's subject to wind drag like every other bullet so it WILL start decelerating immediately, but the extra velocity of the bullet keeps it far clear ahead of the plane. |
|
And if you shoot your gun out of a side helicopter bay the bullet will be traveling forward at the speed of the heli, regardless of how fast it is traveling horizontally. I'm not a door gunner or anything, but I saw a show on it, and they are trained to aim behind the targets, because the bullets will swing forward. Pretty cool.
|
|
Quoted:
Drag acts upon the bullet and starts slowing it down as it travels in whatever trajectory that particular projectile travels at that velocity. Just like any other bullet. View Quote View All Quotes View All Quotes Quoted:
Quoted:
But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? Drag acts upon the bullet and starts slowing it down as it travels in whatever trajectory that particular projectile travels at that velocity. Just like any other bullet. Which is how a plane can shoot itself down with its own gun. |
|
Quoted:
But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? View Quote View All Quotes View All Quotes Quoted:
Quoted:
Fighter jet @ 2,000fps + Bullet out the barrel @ 2,000fps = Bullet going 4,000fps But as soon as the bullet leaves the barrel it is no longer powered while the plane is, so what happens? Okay, it's already been explained correction a few times but you don't quite seem to get it. The initial velocity will be much higher than the plane is traveling (as above). Why? The barrels in the cannon are also traveling forward at supersonic speed. So is the stationary bullet and powder and casing before it is fired. Now, about the 2nd part. So the bullet at it's extraordinarily high velocity will have a lot of drag from the air. So it will be slowing down rapidly. However, since it's initial velocity is so much higher than the aircraft, there will be no problem with the bullets hitting your own plane. Is the plane flying level? They will perceive the bullets dropping off the line of fire at a normal rate, but the forward component of the velocity will reduce more rapidly due to the drag they are experiencing. So the bullets will initially be very fast, slow down rapidly, and drop at a normal rate. If the plane is flying level, the plane will eventually overtake the bullets but they will be beneath the plane. |
|
Quoted:
The speed of sound is irrelevant. Let's perform a thought experiment. A plane is flying at 500 MPH = 733 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is travelling at 2,733 FPS. Now a plane is flying at 1,000 MPH (speed of sound is ca. 761 MPH) = 1,466 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is traveling at 1,466 = 2,000 FPS = 3,466 FPS. "Mach" is irrelevant. Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. View Quote View All Quotes View All Quotes Quoted:
Quoted:
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? The speed of sound is irrelevant. Let's perform a thought experiment. A plane is flying at 500 MPH = 733 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is travelling at 2,733 FPS. Now a plane is flying at 1,000 MPH (speed of sound is ca. 761 MPH) = 1,466 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is traveling at 1,466 = 2,000 FPS = 3,466 FPS. "Mach" is irrelevant. Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. The light would appear to be traveling away from the spacecraft at the relative speed of light whereas to an outside observer the beam would also appear to be traveling at the speed of light relative to the observer. |
|
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. |
|
So a rear firing weapon's projectile is going faster in reverse than forward. Does it drop like a stone or get sucked after the plane?
|
|
Quoted:
There was a plane that actually shot itself down. It fired its cannon level, and then entered a shallow dive, and managed to get under its own bullets, IIRC. View Quote Grumman F11F, if my memory isn't off. Some engineer wasn't thinking ahead, when the flight test of the prototype was planned. The sequence was to test the cannons by firing (while flying level at subsonic speeds), then enter a shallow dive and accelerate to supersonic. Pulled out of the dive just in time to shoot itself down. |
|
Quoted:
The light would appear to be traveling away from the spacecraft at the relative speed of light whereas to an outside observer the beam would also appear to be traveling at the speed of light relative to the observer. View Quote View All Quotes View All Quotes Quoted:
Quoted:
Quoted:
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? The speed of sound is irrelevant. Let's perform a thought experiment. A plane is flying at 500 MPH = 733 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is travelling at 2,733 FPS. Now a plane is flying at 1,000 MPH (speed of sound is ca. 761 MPH) = 1,466 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is traveling at 1,466 = 2,000 FPS = 3,466 FPS. "Mach" is irrelevant. Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. The light would appear to be traveling away from the spacecraft at the relative speed of light whereas to an outside observer the beam would also appear to be traveling at the speed of light relative to the observer. The velocity of light is constant no matter the frame of reference. This is a pretty important point and sorta critical to the Theroy of Relativity. |
|
If I'm travelling at an average speed of 1,200 meters a second, and I fire a gun that has an average bullet velocity of 1,100 meters a second, then how is babby form?
|
|
Quoted:
Thou shalt not add thy velocity to the speed of light. Same principle applies here. View Quote 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. |
|
Quoted:
The velocity of light is constant no matter the frame of reference. This is a pretty important point and sorta critical to the Theroy of Relativity. View Quote View All Quotes View All Quotes Quoted:
Quoted:
Quoted:
Quoted:
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? The speed of sound is irrelevant. Let's perform a thought experiment. A plane is flying at 500 MPH = 733 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is travelling at 2,733 FPS. Now a plane is flying at 1,000 MPH (speed of sound is ca. 761 MPH) = 1,466 FPS. It fires a projectile from its cannon at 2,000 FPS. The projectile is traveling at 1,466 = 2,000 FPS = 3,466 FPS. "Mach" is irrelevant. Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. The light would appear to be traveling away from the spacecraft at the relative speed of light whereas to an outside observer the beam would also appear to be traveling at the speed of light relative to the observer. The velocity of light is constant no matter the frame of reference. This is a pretty important point and sorta critical to the Theroy of Relativity. That's what I said. The speed of light can't be exceeded relative to any observer. |
|
Quoted:
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. View Quote View All Quotes View All Quotes 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. Just so we're clear, Newtonian physics is not able to describe the behavior of light. |
|
Quoted: Velocity of aircraft + velocity of projectile ETA: Damn...TWO seconds View Quote In the flawed Galilean universe, yes that's true. But in the reality of special relativity, it's not quite correct. A small niggle, but if you apply the same principle to faster objects the flaws become serious. |
|
Quoted:
Just so we're clear, Newtonian physics is not able to describe the behavior of light. View Quote View All Quotes View All Quotes Quoted:
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. Just so we're clear, Newtonian physics is not able to describe the behavior of light. I was talking about solid projectiles fired forwards from another object in motion. |
|
|
Quoted:
Grumman F11F, if my memory isn't off. Some engineer wasn't thinking ahead, when the flight test of the prototype was planned. The sequence was to test the cannons by firing (while flying level at subsonic speeds), then enter a shallow dive and accelerate to supersonic. Pulled out of the dive just in time to shoot itself down. View Quote View All Quotes View All Quotes Quoted:
Quoted:
There was a plane that actually shot itself down. It fired its cannon level, and then entered a shallow dive, and managed to get under its own bullets, IIRC. Grumman F11F, if my memory isn't off. Some engineer wasn't thinking ahead, when the flight test of the prototype was planned. The sequence was to test the cannons by firing (while flying level at subsonic speeds), then enter a shallow dive and accelerate to supersonic. Pulled out of the dive just in time to shoot itself down. That's the one. |
|
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?
|
|
Now, if you had instead asked about a spaceship traveling at the speed of light turning on its headlights, that would have been an interesting question. View Quote |
|
At the speed of light, time stops moving forward due to time dilation.
If a spaceship moving at C were to fly to a star 65 light years away from its launch point, 65 years would elapse relative to the launching pad but to the crew, the voyage would be instantaneous. |
|
|
Quoted:
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? View Quote 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? |
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.