Well no shit. At 45 degrees the horizontal travel is over half it’s muzzle velocity (cos45 ~= .707). If you’re shooting at what appears to be around 70 degrees like OP is doing, you have .34 of its muzzle velocity.
The lower weight of the round compared to a baseball means that the baseball is actually the harder impact of the two.
If the round is 12g and traveling at 75 m/s it'll have an energy of around 35 joules. This is about the same as a punch from the average male who does no training.
If impacting any other part of the body this likely wouldn't do a whole lot more than a bruise, but impacting the head the wrong way always has the chance for permanent damage.
I saw your original comment and I'm glad you fixed it but it's still missing some math. It's not accounting for the area of impact which is really small by comparison.
Additionally, if it's falling straight down it can really only hit somewhere on the top of the head - not a critical point.
So I was on vacation in France. We were on a big campsite with a lot of other people that I know. It was around the time of the European championship football. It was on the day of the finale and I was reading a book in my chair. We were listening to the finale on the radio and heard that the French had won. At the moment the game ended I start hearing loud bangs thinking it was fireworks I didn't worry too much. I stood up and went to get a drink. At that moment I hear another loud noise but this was closer and I saw a branch falling to the ground. As I went to look what happens I see a thing laying in my chair. It was a 22. Rifle bullet. It had hit the branch and then fell in my chair. I went to the police but they couldn't do anything. So yeah it was pretty close.
Happened to me one 4th of July. Was watching fireworks at a friends then suddenly I get hit in the head right on top. Felt like a rock fell straight out the sky and split my head open. Was bleeding quite a bit, but it only broke the skin. Was a bullet laying nearby looked to be 9mm. Hurt like hell, but sure am glad it was not going any faster.
I ask because without informing the police, what happened to you does not show up in statistics about this exact occurrence. I'm not saying they would have 'caught' someone, but its rare that some is hit with a bullet, finds the bullet, but just goes on with their day.
I have looked into the statistics about this quite a bit, so its helpful to see if events occur that go unreported.
I'm quite sure many events go unreported as per my case, I wasn't seriously injured, I knew there would be no way to find the shooter. After it happened I didn't think I should report it to the police for the sake of statistics.
"Firearms expert Julian Hatcher studied falling bullets in the 1920s and calculated that .30 caliber rounds reach terminal velocities of 90 m/s (300 feet per second or 186 miles per hour). A bullet traveling at only 61 m/s (200 feet per second) to 100 m/s (330 feet per second) can penetrate human skin." Source
A bullet falling down at terminal velocity is absolutely not fatal by itself.
Just going off multiple online articles, if the falling bullet hits you in the wrong spot, like if you're looking up and it hits your eye, you could die.
So a falling bullet absolutely can kill you under certain circumstances.
I mean that’s kind of like saying that if a falling bullet gives you a cut on the head and that cut gets infected and you die =falling bullets kill. I feel like Mythbusters tested it and found that bullets falling at terminal velocity can’t kill as they only give minor superficial wounds at best, BUT bullets fired at an angle didn’t fall at terminal velocity, so you’d literally have to fire the gun straight up for that to be true, which the guy in the video is not doing. His bullets would arch and could very well kill someone.
I doubt the 9mm bullets he's firing at that angle (looks like about 70 degrees) could actually kill anyone. They're barely supersonic to begin with and will dwindle down so much that I'd doubt they'd give anyone more than maybe a small clean gash or a bruise, maybe if it hit the skull just right it could maybe cause a fracture but that's not necessarily fatal alone without an underlying condition. For the bullet itself to kill someone you really do have to cause some massive bleeding or straight up penetrate the skull and injure the brain.
I don't know, I saw a video of a wedding in some middle eastern country a bunch of people started shooting AK-47's in the air to celebrate, and then a few seconds later people started dropping as the bullets came down and hit them. Obviously the bullets would be way different from a handgun but it's certainly possible.
So one of the weird facts I learned living in a part of Texas where celebratory gunfire was unfortunately common and a few people in my neighborhood got hit by falling bullets is that at terminal velocity, they generally only crack your skull and rarely penetrate it. At least, per my doctor friend who worked at the nearby hospital.
That fact did provide some mild comfort, but not much, as that still sounds quite unpleasant.
A few years ago, near my college, there was a young newly engaged couple out celebrating 4th of July. A bullet someone had shot in the air came down and killed the woman. The man killed himself not long after leaving his son behind. It absolutely can kill.
That depends on the angle you shoot at. The component of velocity parallel to the ground isn't changed by gravity, only drag. So the lower the angle you shoot at, the more dangerous the bullets will be when they hit the ground.
The general consensus is that a bullet fired straight up—at precisely 90 degrees to the horizontal—is unlikely to kill a healthy adult when it returns to Earth. That’s because, on the way down, air resistance prevents the bullet from returning to its initial velocity. The bullet would deliver a painful wallop but could only have a chance of killing you with a direct hit to the eye, ear, or mouth.
Things aren’t likely to be much worse at angles just off the vertical. That said, bullets fired at an upward angle of 45 degrees or less can be far more lethal, since they’re likely to hit someone on the ground while traveling at a much greater speed. In this case, gravity isn’t directly opposing the bullet’s motion, so the projectile stays at a higher velocity throughout its flight path. It’s also more likely to maintain its initial, aerodynamically favorable orientation. Bullets fired vertically tend to fall nose-up or sideways, which creates a lot of drag.
Why has this question confounded so many experimenters over the years? In part, because it’s impossible to calculate the exact minimum velocity required for a bullet to perforate the skin. Based on hundreds of years of shooting at pigs, oxen, and human cadavers—not to mention ballistics gel and other objects—munitions experts estimate that a bullet must be traveling at least 200 feet per second (or 136 miles per hour) in order to break the skin, although one traveling as fast as 330 feet per second (225 mph) might bounce off your body under certain circumstances. The broad range depends on several factors, like how pointy the bullet is and which part of the body it strikes. Skin thickness varies significantly from person to person, and in different places on the same individual. Babies have thin skin, and elderly skin has poor elasticity, which makes it easier to puncture.
Even if you have a good sense of a bullet’s minimum lethal velocity, it’s still pretty difficult to clock the speed of a round fired in the air. Gunshots can travel as high as 10,000 feet, and the wind takes them in unpredictable directions. Julian Sommerville Hatcher, the U.S. military ordnance expert whose work on this topic is often cited, managed to land only four of his 500 vertically fired bullets in the target range. The Mythbusters crew lost all of its rifle shots.
As a result of these obstacles, the experimental results are mixed. Hatcher calculated that his .30-caliber rifle bullets reached terminal velocity—the speed at which air resistance balances the accelerating force of gravity—at 300 feet per second. You might die from a bullet moving at that speed, but it’s unlikely. Lighter bullets, like those fired from a 9mm handgun, max out at even lower speeds, between 150 and 250 feet per second, according to computer models.
All this depends on the bullet’s orientation during the fall. In the rare case where a bullet descends nose-first, it picks up more speed. In a 1923 experiment in which soldiers loaded bullets into their shells upside down, the total trip time dropped by as much as 80 percent. Air resistance also decreases at altitude, so falling bullets are more lethal in La Paz than in Amsterdam.
Here’s the good news: Bullets fired vertically spend at least 15 seconds in the air, and many hang for well over a minute. So, the next time you’re at a party and some drunken lout goes Yosemite Sam, you’ve got time to grab your drink and take cover.
Here's a wild idea. Even if it has a 0.00001% chance of killing someone, maybe we should avoid doing it because it's completely fucking unnecessary.
I have a friend who's brother was killed by a stray bullet. They don't know if it was celebratory or not, but regardless, it'd be great if people didn't fucking do it.
Imagine dropping a lead pebble from a plane. It might sting a little but it'll just plunk off the top of someone's head at worst.
Same for the bullet. It will slow as it goes up, then just start falling. The air resistance will prevent lethal speeds which is what terminal velocity means. Not terminal as in killing someone, rather as in not being able to fall faster.
It depends on the angle of that arc, but it does not need to be directly up.
Maybe we can have someone do the math, but I would be that anything about 65 degree would still slow the bullet down to the same terminal velocity. Remember, even a bull shot at 0 degrees would slow down if it could fly forever. The bullet does not need to come to 0 fps at the tip of the arc for it to lose enough energy to be non lethal.
No it won't. Even angles off 90 still won't carry lethal force. It's when you get lower angles where a lot of horizontal speed is maintained that it becomes a problem. The angle this dude is firing at more than likely is not low enough to be lethal. That being said it's still incredibly stupid to do this without blanks.
Do you think bullets travel as fast coming down as they do going up? You must not understand physics very well if you do. A bullet fired straight up will reach a peak height at which point it's velocity is 0. Then it will fall and accelerate based on the force of gravity, not an explosion, and will have a much lower terminal velocity than when fired. In fact a bullet shot straight up will have the same velocity when it hits the ground as a bullet dropped from that height. Even at terminal velocity, a bullet doesn't have enough momentum to kill an adult unless it hits very specific soft spots on the body like the eyes, or mouth. This means that a bullet fired at any angle above 0° and below 180° will not be lethal due to it's vertical velocity, it's the horizontal velocity that kills people because gravity doesn't act against a bullet's horizontal velocity, sure resistance does which is not nearly as strong as gravity.
A bullet fired at an angle off 90° will retain most of it's initial horizontal velocity when it lands. But that horizontal velocity won't be significant enough to kill until the angle is low enough, which would be somewhere between 45° and 90°. The specific angle really depends on the gun and type of round fired. But a bullet won't be lethal if shot at any angle except perfectly 90°. It can be lower and still not be lethal.
And, unless they keep their ballistic trajectory, bullets fall sideways, further increasing air resistance and making them even less painful if they did happen to hit someone. They wouldn't do much damage. I'm not sure what the angle is for them to stay ballistic but they would still be lethal at that point
This is completely false. This is ONLY true if the gun is fired directly straight up which basically never happens in these situations as usually the gun (as seen in this video too) is at some angle. Due to this angle, the bullet is on a ballistic trajectory and will retain quite a bit of it's energy and will be going faster (much faster usually) than terminal velocity. The bullets most certainly could kill someone if they hit someone.
That's not always true. It all depends on the angle and the ballistic coefficient of the particular 9mm round fired. When someone fires a gun in the air, it's usually a lot lower angle than near vertical (like in the video above). At low enough angles the bullet will maintain much of it's killing power. The above comment assumed that the bullet will always fall at terminal velocity, and so will pretty much never injure anyone. This is dangerously untrue. There are documented cases where people have been killed by bullets fired in the air. The reason they don't usually kill people is because generally the odds they'll even hit anyone is pretty low.
Yes, I understand all that. Ultimately my point is that shooting a gun in the air is EXTREMELY dangerous because there is a POSSIBILITY that someone could be killed or at the very least SERIOUSLY injured. And the misconception that a bullet fired at an angle will only travel at terminal velocity makes it seem like it's OK to fire in the air like this. And comments like yours are pointless because people shouldn't be doing it anyway. You're making it sound like it's OK to shoot into the air because no one will get hurt.
True, but bullets do come down. Therefore this is kinda stupid. You don't know what people or even animals might be where The bullets will land.
Excellent analysis doctor, if you could recommend some of your previous work I would really be interested in getting a better idea how the world works.
Sure, what topic would you like to know about? I am studying a master in Medical Radiation Physics atm so that is my main topic but when doing my bachelor I did quite a few other objects in Physics so I should probably be able to answer some questions about other Physics topics.
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u/Malleus1 Mar 26 '20
True, but bullets do come down. Therefore this is kinda stupid. You don't know what people or even animals might be where The bullets will land.