take a baseball and a lump if impact-fuse detonated C4 that weighs the same as the base ball both will take the equivalent amount of energy to throw and both will land with the same velocity, which will do more damage???
Posted on 04/07/2013 12:05:19 PM PDT by neverdem
No. It’s like comparing a 20mm HE with a 5.56mm: the HE projectile flies slower but carries it energy through its explosive fill (and its steel fragments)The 5.56mm gives its target effects through kinetic energy only.
The unknown is how much of that Mach 7 velocity will be retained at the target. Mach 5 is still plenty fast enough to punch clean through anything light enough to actually move, and most things not!
The Copperhead was a much slower projectile and its terminal guidance was a semi active laser. They were also a dog: lousy long-term storage life and a poor record for properly functioning. They were entertaining though: they made a very distinctive buzz while they were maneuvering around. You would be more accurate if you cited the GPS-guided Excalibur 155mm as your example. But as successful as it has been, it will take a better engineer than you to make it function at hyper velocities.
At low angles of fire, your projectile would be completely burned up before it got very far.same mechanism that makes big meteors into tiny little meteorites. That blanket of air is at its densest at sea level - which where the ships are, of course.
take a baseball and a lump if impact-fuse detonated C4 that weighs the same as the base ball both will take the equivalent amount of energy to throw and both will land with the same velocity, which will do more damage???
You betcha! I can make the accelerometers and perhaps some of the fusing, but the whole package is well beyond any individual engineer's ken, let alone my singular skill set.
We still have enough engineers skilled in the required arts to do it.
We had electronics capable of withstanding the multiple forces in being fired from a high velocity cannon 30 years ago. They have only gotten smaller, lighter, less power hungry and therefore more robust every year since.
Today's engineers have far better tools.
OK. Here’s the math to answer you. Conservation of momentum requires that the total momentum of a system remain constant before and after an “event.” Momentum (p) is equal to mass times velocity (p=mv). If a normal 6” shell (from a WWII-era cruiser) weighs 51kg (I’ll use metric since the math is easier) and has a muzzle velocity of 840 m/s, it’s total momentum is 42,840 N*s. This would be enough to move the HMS Achilles (which had these guns and weighed ~6.5 million kgs) backwards at .006 m/s. Upon impact, the 14kg cordite charge inside would release on the order of 28 MJ of energy.
Let’s assume that the railgun in question was installed on the same cruiser. The 18kg (40lb) projectile leaves the barrel at ~2490m/s (5600 mph). That means it has a momentum of 44,820 N*s, moving the cruiser at .007 m/s. So no difference in recoil (and that’s compared to an old, small shell, not a battleship-type shell with waaaay more recoil).
The impact (which I’ll calculate at both muzzle velocity and half speed, using the formula for kinetic energy: one-half the mass times the velocity squared) could range from 55 MJ to 14 MJ. So, depending on range (which is much farther than the comparable shell... the 6” had a range of 14 miles), it might range from twice to one-half the energy on the regular shell, with many additional advantages.
So, you see, the recoil depends on the velocity, but the kinetic energy on impact depends on the velocity SQUARED.
Therefore, the railgun is by far the more impressive weapon, especially if it continues to progress. And your recoil worries are silly (and border on the mathematically illiterate)...
Deceleration from air friction starts the moment it leaves the gun. Terminal velocity, hence kinetic energy, depends on range.
Then I guess we should just surrender.
The gun must have an equal momentum opposite in direction so the two mometums cancel out and keep the overall momentum of the system 0.Do magnetic rail guns or pulse weapons have recoil?
The preceding scenario is referred to as a collision/momentum transfer in classical mechanics. The key is that no external forces are present. Once a magnetic field is introduced, the system becomes more complicated and can no longer be described as a momentum tansfer/collision. A recoil in the classical sense dose not occur.
There seems to be some ambiguity in these postings about the meaning of the word “recoil.” One can argue that if a .22 pistol, say, were put in a heavy vice strongly attached to heavy structure and fired, that there would be “no recoil” in the sense that - to the naked eye at least - the pistol would not move. But that cannot negate the fact that the bullet fired from the pistol would have a changed the momentum - the product of the mass and the muzzle velocity - of the bullet. And that, one way or another, that momentum change had to come from an equal impulse - the integral of the force exerted by the gas (or, in the case of the rail gun, the magnetic field) on the bullet. The impulse which propels the (relatively very light) projectile must equally act in the reverse direction on the relatively massive gun and, whether via a recoil mechanism or direct mechanical connection, the even more massive ship or earth to which it is attached.All the “recoil” mechanism of the gun can do is act as a filter which reduces the peak of the time history of the impulse to which the gun subjects its mount. That reduction can be essential to the physical durability of the gun mount, but it must concomitantly extend the duration of the impulse so that the impulse still equals the change of momentum imparted to the projectile.
Sorta like adding a rocket booster to a 16" shell...
Well, golly - aren’t we the optimist? Careful reading of my previous posts will tell you that there are more issues than just making the fuze and detonation chain sufficiently miniaturized and robust: the projectile will have to be guided and all that stuff uses up interior space in an already smallish projectile. So what explosive fill will you use? Got anything that will survive the G-loading/EMP/thermal load? I am a “current engineer” and a program manager for advanced technology ballistic projects. I don’t have much patience for large-dollar projects that soak up limited R&D funding and only seem to make good PowerPoint slides.
Wow - what a long way to say “are recoil system distributes the recoil force over time to reduce the instantaneous load on the gun mount”.
That's what I was thinking about. Pentagon Leatherneck wrote, "I don’t believe the recoil from the impulse of firing a 40-lb. projectile will be all that great." I agree if that's the projectile actually deployed.
Regarding recoil, from the Institute of Electrical and Electronics Engineers: Recoil in electromagnetic railguns
Gun designers have long accepted and understood the fact that guns experience recoil when fired, and many ingenious mechanisms have been devised to cope with the problem. But hope springs eternal, and when confronted with a revolutionary new technique for accelerating projectiles, where the accelerating mechanism may be somewhat mysterious, the gun designer hopefully asks, "Does it recoil?"; knowing in his heart that it does. The more difficult question with regard to the electromagnetic (EM) railgun is "Where and how do these recoil forces appear and can their location and distribution be controlled?" That is the topic of this paper.P.S. Don't trust answers from Yahoo or Answers.com.
It doesn't seem to fulfill the definition of a firearm. Maybe they should use the word accelerate instead of fire.
Big whoop. The current administration thinks that the only folks worth shooting at are conservative Christians.
Saddam tried that once.
That's what I'd guess.
Mount the (low angle) railgun on a frictionless puck and see if you don't score an own-goal.
On wate the horizon is 8.5 miles away. 220 miles is WAY beyond visual range.
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