/sci/ - Science & Math

Yes it would.

yes and yes

and why the fuck am i getting blurry captcha? my eyesight is alredy bad as it is

Firing a gun in space: clever mean of propulsion through recoil?

>>3780958
What?

Not a native english, not so good w/ dem words.

http://www.youtube.com/watch?v=ucw2B1i3p7c

This should answer all your questions. No oxygen to combust

>>3780981
cartridges are enclosed, the combustion happens inside.

or are you using a muzzleloader on the moon?

I don't know a lot about guns, but isn't all the gun powder(or whatever it is now) sealed away in the cartridge with a little bit of air? Ye olde guns probably wouldn't fire, but a relatively new gun might.

>>3780992

I meant no oxygen in the surrounding environment. Should not have to explain that.

>>3780992
>muzzleloader
>>3781007
>Ye olde guns
They still would fire on account of having their own oxidiser in the powder in the form of saltpetre.

>>3781012
That does not matter. There's enough oxidizer in a cartridge for traditional guns to work in space just fine, although overheating might be a problem in a vacuum.
The Soviets knew this, and used normal weapons on their military space stations.
http://en.wikipedia.org/wiki/Nudelman-Rikhter_NR-23

>>3780901
Cartridges do not fire because of reactions with air. Gunpowder contains it's own oxidizer. It would react even in a vacuum. I don't believe any material can burn rapidly enough by reacting just with atmospheric oxygen to create an explosion, short of vapors which first must mix with the atmosphere at an appropriate ratio.

>>3780966
I was saying that if your mass is 80kg fire a gun in space, let's say an AK-47 that fires 75 rounds of 8g bullet at 800m/s (thank you, wikipedia), then you would gain a speed of

<span class="math">v=\sqrt{\frac{8g}{80kg} * 75 * (800m/s)^2} m/s[/spoiler]
<span class="math">=\sqrt{10^{-4} * 75 * 64.10^4} m/s[/spoiler]
<span class="math">=70 m/s[/spoiler]

from the recoil.

>>3781085
conservation of momentum.
Mv=nmv
v=nmv/M = 75*0.008*800/80 = 6 m/s

>>3781120
and that is assuming the gun is at your center of gravity. if you hold the gun at your shoulder you start to spin around instead of moving backwards.

>>3781120
Could you use this to "fly"?

Sorry if I sound retarded, but I'm a child, and I want to know all this shit.

>>3781132
Is today a retard day on /sci/ ?

>>3781120
Indeed, sorry about that. I should stick to maths, I seem to do something stupid every time I answer a basic physics question by providing an equation.

>>3781210
I don't get what you don't get about his post. He's kinda right. Depending on the position of the gun relative to you, your momentum would be split between two components, one making you move backward and one making you rotate.

Or did you mean that, as it's retard day on /sci/, it's alright for you to post retarded stuff?

>>3781195
>>3781085
>>3781085
If you're curious as to why that's wrong, that process neglects that the bullets carry away energy.

>>3781195
>>3781195
Sure. If you had a big enough gun you could "fly"

That's essentially what jets do. Except instead of explosions shooting bullets, they fire gasses out of the exhaust. In the end you just need to transfer momentum in one direction, and the recoil (Newton's third law) will propel you in the opposite direction.

>>3781132
>>3781132
Actually you would both spin around and move backwards, but I imagine your spin would be negligible because of the body's rotational intertia. The torque would probably be minimal. But I don't feel like going through an approximate calculation.

>>3781250
>>3781250
If you look up the Vulcan Cannon, I do believe that pilots report feeling the plane slow while the cannon is fired.

>depleted uranium shells at 6600 rounds per minute

>>3781268
The A-10 Thunderbolt's recoil when firing its GAU-8 Avenger causes it to "hover" in place because the force from the gun cancels out the forward thrust of its twin engines.

http://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunderbolt_II

>>3781281
That's actually the plane and gun I had in mind. Got the gun confused.

No oxygen to combust.

If you fired the gun while it was inside a plastic wrapping with air inside it, however, there wouldn't be much stopping either the process of firing or the bullet now heading straight toward who-knows-where. Oh, and you would get blown back through space about half as fast as someone on the receiving end would (if it were a Hollywood movie).

>>3781281
Um no.

It slows it down by ten miles an hour. Of course, to the pilot, it sure feels like it's stopped, but it hasn't. If that were the case, we'd be halfway to Mars on the GAU-64 firing 9x19 meter rounds at the ground.

>>3781300
You're wrong. Rounds have oxidizer in them.

>>3781300
>>3781300
Do you even bother skimming other posts in a thread before you post?

>>3781310
"The recoil force of the GAU-8/A[14] is 10,000 pounds-force (45 kN), which is slightly more than the output of one of the A-10's two TF34 engines (9,065 lbf / 40.3 kN each)."

>>3781310
>>3781310
The recoil force of the GAU-8/A[14] is 10,000 pounds-force (45 kN),[3] which is slightly more than the output of one of the A-10's two TF34 engines (9,065 lbf / 40.3 kN each).[15] While this recoil force is significant, in practice cannon fire only slows the aircraft a few miles per hour.[13]

Still pretty cool that the recoil rivals a modern jet engine in thrust.

This was also pretty awesome

The A-10 engines were initially susceptible to flameout when subjected to gases generated in the firing of the gun. When the GAU-8 is being fired, the smoke from the gun can make the engines stop, and this did occur during initial flight testing.[2] Gun exhaust is essentially oxygen-free, and is certainly capable of causing flame-outs of gas turbines. The A-10 engines now have a self sustaining combustion section. When the gun is fired the igniters come on to reduce the possibility of a flame-out.[13]

>>3781334
Well it wouldn't cause the jet to hover. It would be like if the engine stopped working, and since the Avenger tears through ammo like a fat guy cannon balling into a 4 foot deep pool, it wouldn't slow it down for too long. Sure, I'll give you the fact that engine on full blast won't propel now, and the speed is dropping quicker than normal because of the gun, but it is still several ton fighter jet flying at fucking 600 miles an hour.

And I'm not saying a gun wouldn't propel you through space, I'm saying the GAU-8 does not cause the aircraft to hover. Normal attacks that the pilots use usually slow the aircraft down by 10 miles an hour, but considering it sprays for 4~ seconds and it's slowing down an 11000 kg plane moving at speeds above 800 kmph, that shit is pretty fucking powerful.

But not enough for it to hover.

Which is the point I'm trying to make.

Fuck yo' shit, I don't know how to figure out dem technical maththings of yours.

How many years do you study for stuff like this?

>>3781490
Like this:
>>3781085
?

That's motherfucking 9th grade.

>2011
>There are actually people that think you can't shoot firearms in oxygen-deprived environments

>i dont want to live on this planet anymore

>>3781664
We ain't learned shit of this.
9th grade is like probability calculating and algebra.