Post: #76

He should have worn body armor at least, don't these people play video games?

Post: #77

(12-21-2017 10:42 AM)RoastBeefCurtains4Me Wrote:  I think with a desert eagle round, even if the book stopped it, you'd feel like somebody smacked you in the chest with a sledge hammer, possibly still enough to stop your heart.

Popular myth from what I understand.

The laws of physics indicate that the force of the impact cannot by definition be greater than the force of the recoil when firing the gun.

Guys going flying when a hit by a shotgun is pure Hollywood nonsense. A hit from a gun can knock a guy down but only the same way it would if he held the butt/grip of the same gun to his chest, took a backward stance ("oh crap, I'm about to be shot"), fired the gun and took the recoil as such.

Even from a 50 cal deagle, a book large enough to stop it would leave the holder feeling like he'd received a solid punch to that same book. Nothing more.

Post: #78

^ that is interesting, but I think a larger factor would be the rate of decceleration, and how concentrated that force is. A small book suddenly jammed into your chest at a very rapid speed would probably crack a few ribs, since there isn't much flex there. But yes your whole body may not be forced very far, more likely the involuntary muscle shock your body might make.

Post: #79

Quote:She says she fired from about a foot (0.3 meters) away and then fled the house screaming.

I'll bet she's useful in an emergency she didn't cause, too.

Post: #80

(12-28-2017 05:59 AM)Leonard D Neubache Wrote:  

(12-21-2017 10:42 AM)RoastBeefCurtains4Me Wrote:  I think with a desert eagle round, even if the book stopped it, you'd feel like somebody smacked you in the chest with a sledge hammer, possibly still enough to stop your heart.

Popular myth from what I understand.

The laws of physics indicate that the force of the impact cannot by definition be greater than the force of the recoil when firing the gun.

Guys going flying when a hit by a shotgun is pure Hollywood nonsense. A hit from a gun can knock a guy down but only the same way it would if he held the butt/grip of the same gun to his chest, took a backward stance ("oh crap, I'm about to be shot"), fired the gun and took the recoil as such.

Even from a 50 cal deagle, a book large enough to stop it would leave the holder feeling like he'd received a solid punch to that same book. Nothing more.

Ah, the perfect post to let my inner physics nerd come out. Basically there are two things at play here, kinetic energy(1/2mv^2), and momentum(mv). If you were in space and shot someone, you would fly back, and the guy you shot would go in the other direction at the same speed. Momentum is shared between you and the bullet once fired, and then you and the other guy once he's hit.

Kinetic energy is a different beast all together. Just because your final states are the same, doesn't mean you took the same path to get there. The bullet is accelerated over the 6 inches or so of the barrel, and the gun/you are pushed back with the same force as on the bullet, however due to your bigger mass, you don't accelerate back nearly as much. Now, if the bullet also slows down over 6 inches as it enters say a block of ballistic gel being held by someone, the forces would be similar to a recoil. However, bullets typically slow down considerably faster and less uniformly than that if they hit something hard, and that's what responsible for the truly huge forces generated, to the extent of pancaking a bullet.

The dominating factor is time/distance to slow down. The shorter it is, the higher the instantaneous forces. Picture a catcher catching a fast ball with a few inches of give/padding of the glove, vs what the pitcher experienced with a wide arching pitch over 2 feet, vs what the batter feels when it hits his sternum. The instantaneous, localized forces are well in excess of what it would take to cause someone to go flying, however because they're concentrated on a small area, and for such a brief duration, that does not happen.

Crumple zones, air bags, giant piles of hay for skydivers - all work with the same idea. Instead of decelerating in inches, you do it over feet, and reduce the forces generated by an order of magnitude. Stress concentration factors such as being hit by the corner of a thrown book vs the side also complicate things, but that's the jist. So to answer your question, sort of.

As for the actual story, I'm not sure this is a case of a pussy pass. It's more just a case of stupid and symptomatic of societal problems that values youtube stardom over physics class. Prison is not meant to be punitive, and the way to avoid such a situation in the future isn't to send her there with willful murderers, but to a mechanics of materials class. Sometimes there's nothing more to it than a bad idea, poorly researched, done for little upside, that resulted in a sad outcome.

Post: #81

(12-28-2017 01:16 PM)Seadog Wrote:  

(12-28-2017 05:59 AM)Leonard D Neubache Wrote:  

(12-21-2017 10:42 AM)RoastBeefCurtains4Me Wrote:  I think with a desert eagle round, even if the book stopped it, you'd feel like somebody smacked you in the chest with a sledge hammer, possibly still enough to stop your heart.

Popular myth from what I understand.

The laws of physics indicate that the force of the impact cannot by definition be greater than the force of the recoil when firing the gun.

Guys going flying when a hit by a shotgun is pure Hollywood nonsense. A hit from a gun can knock a guy down but only the same way it would if he held the butt/grip of the same gun to his chest, took a backward stance ("oh crap, I'm about to be shot"), fired the gun and took the recoil as such.

Even from a 50 cal deagle, a book large enough to stop it would leave the holder feeling like he'd received a solid punch to that same book. Nothing more.

Ah, the perfect post to let my inner physics nerd come out. Basically there are two things at play here, kinetic energy(1/2mv^2), and momentum(mv). If you were in space and shot someone, you would fly back, and the guy you shot would go in the other direction at the same speed. Momentum is shared between you and the bullet once fired, and then you and the other guy once he's hit.

Kinetic energy is a different beast all together. Just because your final states are the same, doesn't mean you took the same path to get there. The bullet is accelerated over the 6 inches or so of the barrel, and the gun/you are pushed back with the same force as on the bullet, however due to your bigger mass, you don't accelerate back nearly as much. Now, if the bullet also slows down over 6 inches as it enters say a block of ballistic gel being held by someone, the forces would be similar to a recoil. However, bullets typically slow down considerably faster and less uniformly than that if they hit something hard, and that's what responsible for the truly huge forces generated, to the extent of pancaking a bullet.

The dominating factor is time/distance to slow down. The shorter it is, the higher the instantaneous forces. Picture a catcher catching a fast ball with a few inches of give/padding of the glove, vs what the pitcher experienced with a wide arching pitch over 2 feet, vs what the batter feels when it hits his sternum. The instantaneous, localized forces are well in excess of what it would take to cause someone to go flying, however because they're concentrated on a small area, and for such a brief duration, that does not happen.

Crumple zones, air bags, giant piles of hay for skydivers - all work with the same idea. Instead of decelerating in inches, you do it over feet, and reduce the forces generated by an order of magnitude. Stress concentration factors such as being hit by the corner of a thrown book vs the side also complicate things, but that's the jist. So to answer your question, sort of.

As for the actual story, I'm not sure this is a case of a pussy pass. It's more just a case of stupid and symptomatic of societal problems that values youtube stardom over physics class. Prison is not meant to be punitive, and the way to avoid such a situation in the future isn't to send her there with willful murderers, but to a mechanics of materials class. Sometimes there's nothing more to it than a bad idea, poorly researched, done for little upside, that resulted in a sad outcome.

Seadog is correct. I had looked into this years ago out of nerd curiosity, and indeed, kinetic energy goes up with the square of the speed, so the speed of the bullet gives it its power. The mass also matters, which is why a 50 cal bullet would have a hell of a punch.

I just googled what it feels like to be shot with a bullet proof vest, and the answer by cops and others who have experienced it is that it feels like getting hit by a baseball bat. Now this is probably more ordinary sized rounds, that a cop's bullet proof vest can actually stop. I doubt they could survive a Desert Eagle round with those vests.

So, I think a sledge hammer is probably a pretty good estimate.

http://www.ponderweasel.com/shot-wearing...roof-vest/

Post: #82

She got 90 days in prison in 10-day increments over 30 years, plus 90 days of house arrest.

http://www.startribune.com/minnesota-pro...476861643/

Post: #83

(03-15-2018 10:21 PM)BlueMark Wrote:  She got 90 days in prison in 10-day increments over 30 years

Post: #84

(12-27-2017 11:44 PM)eradicator Wrote:  He should have worn body armor at least, don't these people play video games?

Contrary to what hollywood and video games would have you believe, even if a bullet doesn't penetrate body armor, you can still get seriously injured and in some cases killed depending on the round.

Post: #85

I take with a grain of salt the claims that the rounds are not downpowered but these men are still not being battered around as if struck by clubs.

As I said before, the equivalent of being punched. A gun will not deliver more energy forward than it does in recoil backward. The difference in outcomes probably comes down to this. Like being punched, if you're expecting it then your body hardens appropriately and it's not that bad. If you're not expecting it then that same punch can land you on your ass with the wind knocked out of you.

I have spent many a night shooting large and small animals with large and small guns. Of hundreds if not thousands of shots I have yet to see a bullet decisively move the animal struck. If the animal moves when shot it is almost invariably due to a muscle spasm and the direction it moves is typically straight up. This goes for shots that deliver their full energy and shots that go straight through. Shots that stop almost immediately on bone and shots that stop through inches of flesh.

The only time I've seen a gun noticeably move an animal in and of itself was a 12 gauge shot delivered to a roo at short range that was old and we suspect incredibly sick. It simply knocked it over as if it had been given a solid push.

Post: #86

(03-16-2018 09:28 AM)Leonard D Neubache Wrote:  I have spent many a night shooting large and small animals with large and small guns.

Are you trying to get revenge for the Emu War or something?

Post: #87

Too soon, Eel.

Post: #88

(03-16-2018 09:28 AM)Leonard D Neubache Wrote:  



I take with a grain of salt the claims that the rounds are not downpowered but these men are still not being battered around as if struck by clubs.

As I said before, the equivalent of being punched. A gun will not deliver more energy forward than it does in recoil backward. The difference in outcomes probably comes down to this. Like being punched, if you're expecting it then your body hardens appropriately and it's not that bad. If you're not expecting it then that same punch can land you on your ass with the wind knocked out of you.

I have spent many a night shooting large and small animals with large and small guns. Of hundreds if not thousands of shots I have yet to see a bullet decisively move the animal struck. If the animal moves when shot it is almost invariably due to a muscle spasm and the direction it moves is typically straight up. This goes for shots that deliver their full energy and shots that go straight through. Shots that stop almost immediately on bone and shots that stop through inches of flesh.

The only time I've seen a gun noticeably move an animal in and of itself was a 12 gauge shot delivered to a roo at short range that was old and we suspect incredibly sick. It simply knocked it over as if it had been given a solid push.

Wouldn't the impact be different when the bullet is stopped suddenly than when it penetrates soft flesh?

Post: #89

(03-16-2018 11:02 PM)RoastBeefCurtains4Me Wrote:  ...

Wouldn't the impact be different when the bullet is stopped suddenly than when it penetrates soft flesh?

Does a bullet move a 100 kilo metal plate more than it moves a 100 kilo bag of sand?

Pretty much no.

The speed difference is literally the blink of an eye, and even a bullet stopped in kevlar is still compressing and displacing a lot of flesh on the other side of the vest while it comes to a stop.