silly question

Chaz88 said:
The velocity of the projectile would not be quite as impressive as some think. Because if you are floating in space when you fire it the energy would be divided between pushing the projectile in one direction and you in the other.
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Sorry, Chaz, but there won't be much difference at all in the muzzle velocity of a bullet fired in space from one fired on earth. It's the mass of the firearm-human-bullet system that counts, not their weight on earth vs weight in space. The inertia of the firearm-human combination will be practically identical in either location so they won't go careening backwards when the firearm is fired (given a nominal firearm, not a howitzer ;) ).

peetzakilla said:
It depends on where in space you are.
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Of course it does, but I covered that with the word "almost". I decided not to go into gravitational constants, distance from earth, and all that. The sentence "So, there really is gravity everywhere" is the main point I was making.

[You keep adding to your post!]
If you were, for example, halfway between earth and mars I'm not sure if the sun's gravity would be enough to bring a bullet back before it exited the solar system in theory. Probably it would but that's just a guess.
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Your guess is correct. No bullet fired from a normal firearm is going to have enough velocity to escape the sun's gravity. For example, comets have velocities many magnitudes higher than any bullet from a gun when in the middle of their orbit, yet they can't escape the sun's gravity on their outward travels.

There are locations in near space where the earth-moon-sun gravity will balance out and will have the appearance and feel as if there is no gravity anywhere, but it's an illusion. (They're called Lagrangian points - a very interesting concept if you wish to look it up.)
 
Sorry, Chaz, but there won't be much difference at all in the muzzle velocity of a bullet fired in space from one fired on earth. It's the mass of the firearm-human-bullet system that counts, not their weight on earth vs weight in space. The inertia of the firearm-human combination will be practically identical in either location so they won't go careening backwards when the firearm is fired (given a nominal firearm, not a howitzer ).
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Did not mean to imply that energy would be divided equally between projectile and shooter. But without friction to hold the person in place some of the energy is going to push the person in the opposite direction of the projectile. Would probably be just a bit more energy than you would absorb from recoil on earth. Unless I am completely confusing the physics involved and I will admit that could be the case.
 
Unless I am completely confusing the physics involved ...
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You are, but it's understandable. It seems like the friction of the person standing on the earth would make a big difference, but it doesn't - for normal firearms. If you're firing a big boomer with a heavy fast bullet like a T-Rex .577 or a Nitro Express, for example, then yes, you would be propelled backwards in space as opposed to being bowled over on your backside on earth. :) But for ordinary handguns, you wouldn't be.

Let's use a little thought example - if you stepped into shoes that were nailed to the floor and fired a 1911 straight ahead, would you be pushed over rotating about the point where the shoes are attached to the floor? Now, lets have you standing balanced on some frictionless ball bearings on the floor. When you fire the same gun, do you think you will move very fast backwards?

Even so, your initial premise implied that the muzzle velocity would be appreciably lower in a frictionless situation and that's what I was addressing. It really wouldn't - it would almost be unmeasurable given all the other variables inherent in ammo and firearms. The recoil is practically the same in both situations and therefore the muzzle velocity is also.
 
So it is more a function of available energy acting in opposition to available mass and the mass overcomes the energy in conventional caliber guns?
 
Since I decided to go to college many years after I should have I will be taking a physics class soon. Now I can get homework help and firearms knowledge in one stop.:)
 
I read in one of my many books about the soviets actually firing guns in space. I do not remember the particulars of it, but I do remember they fired and worked as they were supposed to.

It could have been part of their offensive satellite program or something. I am sure the US has done the same thing.

But just think how big the trigger guard would have to be on that thing!
 
Wasn't the Russian gun issued because they once came down off the landing site and wolves wanted to eat them?

Also, there was a little stink about the International Space Station having that gun in it for the Russian craft?
 
But without friction to hold the person in place some of the energy is going to push the person in the opposite direction of the projectile.
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You need to learn the difference between energy and momentum.
 
You need to learn the difference between energy and momentum.
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I don't think so?? Without the energy of the shot doing work on the projectile and the person there would be no vector with direction or magnitude.
 
Chaz,

Energy (kinetic) is not necessarily conserved. Momentum is ALWAYS conserved. The total momentum of the gun/powder/bullet/person system starts at (frame of reference) zero. If the bullet and powder go one way with "X" momentum, the person and gun go the other way. However, since momentum is a function of only mass and speed, the much lighter bullet gets "all" the speed and the much heavier person gets very little speed.

For simplicities sake, if the person weighs 1,400,000 grains (200 pounds) and the bullet is 140 grains with a velocity of 2000 fps, the person will be going just 0.2 fps.

(Ignoring rotation and other such things for simplicity)
 
It should work - gun power has an oxidizer built in - it doesn't rely on O2 gas to go "boom". Several problems would have to be overcome.

1. External pressure would be greater than cartridge's internal pressure. Either the cartridge would have to be well sealed, or loaded in a vacuum to avoid rapid deformation by change in pressure.

2. Absolutely no moisture could be in the mechanism or cartridge. For that matter, no oil or lubricant, other than perhaps dry lube. It would most likely freeze instantly and crystallize.

3. You wouldn't have to wear hearing protection.:)
 
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