What Would Happen If You Shot a Gun in Space? (Space.com article)

[remman]

And I now want to shoot jupiter with a highly explosive device (maybe a grenade launcher would do the trick) just to see what happens when a 40mm grenade impacts and explodes at 134,216 mph...

 

[JettaKnight]

I would say the bullet would continue to accelerate until it hit something!

Just like on earth, acceleration halts when the bullet leaves the muzzle. Velocity will continue to hold steady.

This assumes deep space. If you're in orbit (like a space craft or even the moon), the velocity depends on gravity of the earth. Shoot at the right angle and that bullet will orbit earth for years, just like any satellite. Now, what angle? That's rocket science.

 

[rhino]

Rhino, I expect a complete free body diagram delivered to me tomorrow night at the NRA banquet.

I have to teach my MATH118 class tonight!

 

[rhino]

I would say the bullet would continue to accelerate until it hit something!

You mean when it gets close to something big like Jupiter, or while it's still far from any significant gravitational fields? If the latter, once it exits the barrel, no forces are acting, so it will continue with constant velocity (speed and direction). Newton's 1st.

 

[Mr Evilwrench]

The bullet would leave the muzzle at a velocity approximately the same as it would in the atmosphere, but there is little gas in space to slow it down, so it could travel for hundreds of light years before slowing significantly. It would, however, interact gravitationally with anything it got "close" to, bending its path this way and that, maybe capturing or absorbing it.

The shooter would have that "equal and opposite" reaction to the ejection of the mass of the bullet, plus any residual thrust from the gases. Now, unless the boreline exactly intersected the center of mass of the shooter, more or less of the energy would go into torque, depending how far it is from intersecting. This would send the shooter tumbling and spinning, in addition to moving.

 

[hbarnett1]

Ask captain Kirk,He could tell you.

 

[Mosinowner]

F=MxA so according to this a 800 grain 50 caliber round fired in space would exert 20,195 Joules on the shooter? Then would to continue to fly until it hit the closest planetary mass. Or according to v = H0D the bullet would keep on flying forever disregarding the pull of plants because of the speed at which it travels.

 

[hooky]

I have to teach my MATH118 class tonight!

118 used to be Finite at IU. Improved my card playing by leaps and bounds.

 

[Audie Murphy]

F=MxA so according to this a 800 grain 50 caliber round fired in space would exert 20,195 Joules on the shooter? Then would to continue to fly until it hit the closest planetary mass. Or according to v = H0D the bullet would keep on flying forever disregarding the pull of plants because of the speed at which it travels.

 

[Mosinowner]

Whats so complicated?

 

[rhino]

F=MxA so according to this a 800 grain 50 caliber round fired in space would exert 20,195 Joules on the shooter? Then would to continue to fly until it hit the closest planetary mass. Or according to v = H0D the bullet would keep on flying forever disregarding the pull of plants because of the speed at which it travels.

Probably don't want to think in terms of that version of Newton's 2nd Law, plus Joules are unit of energy, which you would not get from that.

Instead, you want to think in terms of conservation of momentum. Assuming the astro is stationary before firing, the total momentum of the system, p = M*v, is zero since v = 0.

After firing, the total must still be zero, so:

p_bullet + P_gasses + p_astronaut&gun = 0

m_b*v_b + m_g*v_g + m_astro&gun * v_astro = 0

Then solving for the velocity of the astronaut:

v_astro = - (m_b*v_b + m_g*v_g) / m_astro&gun


You could probably get a good estimate by combining the mass of the bullet and powder charge and assuming they exit the barrel at the same velocity.

You'll want to convert the mass of the bullet and powder in grains to kilograms and use m/s for velocities to make it simpler.

 

[Mosinowner]

Probably don't want to think in terms of that version of Newton's 2nd Law, plus Joules are unit of energy, which you would not get from that.

Instead, you want to think in terms of conservation of momentum. Assuming the astro is stationary before firing, the total momentum of the system, p = M*v, is zero since v = 0.

After firing, the total must still be zero, so:

p_bullet + P_gasses + p_astronaut&gun = 0

m_b*v_b + m_g*v_g + m_astro&gun * v_astro = 0

Then solving for the velocity of the astronaut:

v_astro = - (m_b*v_b + m_g*v_g) / m_astro&gun


You could probably get a good estimate by combining the mass of the bullet and powder charge and assuming they exit the barrel at the same velocity.

You'll want to convert the mass of the bullet and powder in grains to kilograms and use m/s for velocities to make it simpler.

True. I couldn't calculate the mass of the round since M=DxV and I don't know the density of the round or the volume. I'll use metric next time

 

[Clay]

Probably don't want to think in terms of that version of Newton's 2nd Law, plus Joules are unit of energy, which you would not get from that.

Instead, you want to think in terms of conservation of momentum. Assuming the astro is stationary before firing, the total momentum of the system, p = M*v, is zero since v = 0.

After firing, the total must still be zero, so:

p_bullet + P_gasses + p_astronaut&gun = 0

m_b*v_b + m_g*v_g + m_astro&gun * v_astro = 0

Then solving for the velocity of the astronaut:

v_astro = - (m_b*v_b + m_g*v_g) / m_astro&gun


You could probably get a good estimate by combining the mass of the bullet and powder charge and assuming they exit the barrel at the same velocity.

You'll want to convert the mass of the bullet and powder in grains to kilograms and use m/s for velocities to make it simpler.

and now you see why I was so disappointed you didn't go to the nra banquet! man I like statics and dynamics!

 

[superjoe76]

What Would Happen If You Shot a Gun In Space?

It could possibly make a Big Bang, but thats just my theory!

 

[rhino]

and now you see why I was so disappointed you didn't go to the nra banquet! man I like statics and dynamics!

And really, who doesn't?

Next time . . . there will be more banquets and more opportunities for me to wax pedantic . . .

 

[rhino]

there will not be much recoil

Why not?

You'd have the exact same recoil impulse as you would on Earth. The difference is, in space you have no way to resist the impulse and you'd be propelled away from the shot.