Physics minds in here please.

[Zip]

Me and a friend have been arguing about this.

If you get shot will the bullet push yyou make or make you go flying?

My thinking of this is the bullet is too small and doesnt have the size to send someone flying back and will just enter your body and you will drop to the ground out of pain and damage to you body.

Is my thinking correct?

 

[Cold_And_Miserable]

Me and a friend have been arguing about this.

If you get shot will the bullet push yyou make or make you go flying?

My thinking of this is the bullet is too small and doesnt have the size to send someone flying back and will just enter your body and you will drop to the ground out of pain and damage to you body.

Is my thinking correct?

For example:
A shotgun fires 28 grams of lead shot going at 400m/s that has 11.2Ns of momentum. A person that weights 80kg will move backwards at 0.14m/s or 0.315 mph.

 

[SourChipmunk]

For example:
A shotgun fires 28 grams of lead shot going at 400m/s that has 11.2Ns of momentum. A person that weights 80kg will move backwards at 0.14m/s or 0.315 mph.

The other way around, the 5.56mm ball round fired from an M16 is designed to be so lightweight that when it enters the body, it ricochets off bone and other hard tissues causing as much internal damage as possible.

So it completely depends on what's being fired, and from what distance.

In the movies, we see a shotgun blast throw a guy through a door or window. That may be a little excessive, but PanMaster's example shows there is some motion.

 

[Memphis]

I take it you don't get MythBusters down there?

 

[Sleepy]

Something to remember is that for every action there is a reaction. So the shooter is subject to the same 'kick' as the target. So if a bullet had enough momentum to throw the target back it would also throw the shooter back.

 

[gord]

Definitely depends on what your getting shot by..

If you got shot by an armour piercing round you probably wouldnt move unless it hit bone, which would fracture most of the surrounding bones and would cause you to stumble back.

If you got hit by a hollow-point bullet you could have a huge hole blown out of you from a smaller bullet, which would definitely push you backwards..

 

[Conscript]

The entire idea that bullets throw people aorund is hogwash, but everyone thinks its real due to Hollywood. As stated, every action has an equal and opposite reaction. So any gun powerful enough t throw the voctim around would do the same to the person firing the gun.

Bullets travel at extreme velocties, yes, but they are also very light and very small. There is no way they are able to move a mass like a human target.

Stumble backward - thats more likely to happen. But usually it will be from the simple act of being shot, the shock causing you to buckle in pain or to drop. It unlikely to be the bullet pushing you.

Also, remember the bullet penetrates the body, which means not all the energy is transferred. Anyone who has fired an air rifle at tin can or a bottle will know, sometime it seems as if you've missed, because the pellet will pass straight through the object rather than knocking it down. Read accounts of people getting shot whilst wearing Kevlar - in some cases, it leads to the victim actually feeling more impact from the bullet, as the vest stops the bullet and soaks up the momentum, transferring it to the wearer.

If anyone wants some help carrying out experiments or something, I'd happily volunteer to shoot at you all day

 

[PhilthyPhil]

The entire idea that bullets throw people aorund is hogwash, but everyone thinks its real due to Hollywood. As stated, every action has an equal and opposite reaction. So any gun powerful enough t throw the voctim around would do the same to the person firing the gun.

While it is true that bullets can't knock people over, it can't be proved using Newtons 3rd law. 3rd law pair forces occur simultaneously, recoil and bullet impact forces do not. The recoil force occurs before the bullet hits the target and is smaller in magnitude but lasts longer (typically).

You really have to look at it as conservation of momentum. Recoil will give the shooter backwards momentum equal to the forward momentum of the bullet and hot gases produced when the powder is ignited. Since the victim is only hit by the bullet and not the gas the momentum transfered to the victim will always be less than that transfered to the shooter. Hence if the shooter is not knocked backwards then the victim can not be.

 

[daz]

Hence if the shooter is not knocked backwards then the victim can not be.

Of course, all things being equal. The shooter may be standing in a stance/position of greater stability, whereas usually you're not expecting to be shot, so a bullet to the chest could throw you off balance.

 

[gord]

Then again, if you got shot by an RPG.. the guy firing the rocket doesnt go half as far and in as many directions as the person catching it..

 

[hungryhungry123]

Since the victim is only hit by the bullet and not the gas the momentum transfered to the victim will always be less than that transfered to the shooter. Hence if the shooter is not knocked backwards then the victim can not be.

I thought I heard that some guns have springed sliding parts which soak up some of this recoil?

 

[Shoseki]

I have seen footage of people being shot from a helicopter gunship, they are often literally blown clean out of their clothes, let alone off their feet.

Not nice.

 

[PhilthyPhil]

Of course, all things being equal. The shooter may be standing in a stance/position of greater stability, whereas usually you're not expecting to be shot, so a bullet to the chest could throw you off balance.

I think all this really does is improve aim. You can certainly fire a shotgun standing normally and it won't knock you over, I would assume it is the same with other guns although I've not tried.

Then again, if you got shot by an RPG.. the guy firing the rocket doesnt go half as far and in as many directions as the person catching it..

As the name suggests an RPG is not a gun, it is compleatly different since the warhead is rocket propelled.

 

[jezsoup]

As the name suggests an RPG is not a gun, it is compleatly different since the warhead is rocket propelled.

ARGHHH what he said was a bit of light hearted humor dont over explain/anyalise it GRRRR just giggle and have done with

 

[Conscript]

I have seen footage of people being shot from a helicopter gunship, they are often literally blown clean out of their clothes, let alone off their feet.

Not nice.

That's a different kettle of fish. The Apache, for instance, carries a 30mm chain gun. That, certainly, would knock you around. Were talking about hand held weapons, not weapons designed for cutting through tanks

 

[Glaucus]

NO no gun will make you fall or fly. Not even shotguns or high-powered snipers. The problem is the bullets way next to nothing, so have little kenitic energy. And when a bullet hits it penetrates or goes straight though thus wasting energy. A bullit simply doesn't have enough power to push you back.

 

[Sleepy]

Of course, all things being equal. The shooter may be standing in a stance/position of greater stability, whereas usually you're not expecting to be shot, so a bullet to the chest could throw you off balance.

There use to be a guy, bullet proof vest salesman? who would let people shoot him in demo's. Even when standing on one leg he never lost his balence.

A lot of people fall over when they've been shut cos that is what they've been programed to do by TV. Unless shot in the heart or brain stem a bullet is not instantly fatal, it takes a while to bleed out.

 

[gord]

ARGHHH what he said was a bit of light hearted humor dont over explain/anyalise it GRRRR just giggle and have done with

"No ma'am, we at the FBI dont have a sense of humour we're aware of."

NO no gun will make you fall or fly. Not even shotguns or high-powered snipers. The problem is the bullets waysp next to nothing, so have little keniticsp energy. And when a bullet hits it penetrates or goes straight though thus wasting energy. A bullitsp simply doesn't have enough power to push you back.

But what you said at the end contradicts your post, i think you meant bullets do have enough power to push someone back just not the size. Because if you fired a metal wall at someone, that would push them back..