Shooting in the sky, can the bullet fall to kill people? This question has been discussed on major websites, but few can give an exact answer. After all, it is very difficult to do a verification test. Now there is really evidence: on the evening of September 3, local time, some Afghan Taliban soldiers fired in the sky to celebrate in the urban area of Kabul, killing 17 civilians and wounding 41 others. After the incident, the Taliban have asked soldiers to stop firing their guns in the sky to avoid wasting weapons and ammunition and injuring civilians. In addition to feeling sympathy for civilian casualties, when this kind of thing happened, I also felt it was really strange!
Many armed personnel like to shoot into the sky
However, this matter is enough to put an end to the problem that has been discussed on the Internet: from the facts, shooting into the sky can really kill people! Of course, an attribute must be added: "Under certain conditions." Because the action of firing a gun to the sky is very broad, the narrowest meaning refers to shooting the gun vertically upwards, but in fact it is impossible to be completely vertical. There must be an angle between the vertical and the angle, and this angle may be very large, so that the bullet will be With a considerable horizontal speed, it is not surprising to kill people after landing.
The Kabul shooting incident caused dozens of deaths and injuries
In fact, there was a precedent for this kind of thing. In 2012, when the Filipinos celebrated the New Year, a large number of police shot in the sky, resulting in 1 death, 60 People were injured. In wars, machine guns do have the tactics of using large elevation angles to "beyond shooting" to kill and injure the enemy.
However, there is no difficulty in discussing this situation. What Ren Ma Jun will discuss today is the most stringent "vertical upward" firing. Can the bullet kill people after it hits the ground?
Heavy machine guns have a transcending shooting tactic
First of all, we have to determine which gun to use. The difference between different guns is very big! For example, if you use an ordinary pistol, you don’t need to discuss it. In the " rumors terminator" program, a group of wealthy and leisurely Americans once did an experiment. They used a fixed pistol to shoot vertically upwards. The bullet did not fall back to its original place under the cross wind and disturbance, but it made a small hole in the mud.Americans think that in this case, it is not possible to shoot through pigskin, so it is unlikely to kill people, but it may be injured if it is hit, and it will be very painful!
This conclusion can be guessed without experimenting, because the mass of the pistol is relatively small, and the key is its low initial velocity. The well-known Beretta 92F pistol has a rate of 375 meters per second, so it can’t fly much higher. The speed of falling under the effect of air resistance will not be too high. But if it were not a pistol, the situation would be very different.
Taliban soldiers have a large number of AK47 series assault rifles. They use 7.62X39mm intermediate power bullets. Some large guns, such as 14.5mm anti-aircraft machine guns, have several steps higher than AK47 bullets. Today we will use pistol bullets. Calculate the mid-power rifle bullets and the high-power high-power bullets to see what effect they will cause when they fall.
7.62X39 bullets used by AK47
Let’s take a look at how the bullet will go through when the gun is shot vertically upwards. When the cross wind is not considered, after the bullet exits the chamber at a certain speed, it will gradually decelerate under the action of gravity and air resistance. The higher the speed, the greater the air resistance. In addition, if the musket is not used, it will rotate at a high speed to increase stability. As a result, the velocity of the bullet in the vertical direction will sooner or later be reduced to zero and rise to a certain height.
Then, the bullet will start to fall from this height and gradually accelerate under the action of gravity. But at this time the direction of air resistance will change to the upward direction, hindering the acceleration of the bullet. If the height is infinitely high and the atmosphere is infinitely thick, the air resistance will eventually balance with gravity, and the bullet will move into a uniform motion. But this condition is difficult to achieve. Generally speaking, the air resistance will be less than the resistance, and the bullet will continue to accelerate before it hits the ground.
However, whether the warhead landed upside-down, landed upside-down, or rolled to the ground is related to its rotation speed. It is really not clear without a computer simulation, and it will also be affected by various disturbance factors. . Therefore, Jun Majun used a simplified method and only considered two cases: once the warhead fell down, and the warhead fell down again, it should also explain the problem.
The bullet will rotate when flying,There will be huge air resistance
. Let’s just do it. Let’s choose three typical bullets: 9X19mm Bara Bellum pistol fired by Beretta 92F pistol, and 7.62X39mm middle bullet fired by AK47 Power rifle bullets, and 14.5X114 mm high machine bullets fired by a certain type of anti-aircraft machine gun, roughly calculate the flight process when they shoot vertically upwards, and their kinetic energy when they land to judge the lethality.
To calculate, you must first know the mass, ejection speed, shape and drag coefficient of these bullets. The first two are easy to find on the Internet. For example, the muzzle velocities of the three bullets are 375m/s, 710m/s and 945m/s respectively. Surprisingly, the 14.5mm high-machine bullet has a warhead weighing 63.6 grams, which is quite heavy. The first two are between 7 and 8 grams. However, the shape and drag coefficient (or elastic coefficient) are more difficult to find. The man and horse looked for the ballistics book ("Practical Ballistics", Wang Changming, Weapon Industry Press) to find the answer.
Different types of bullets are very different
The most important thing here is the calculation of air resistance, which is closely related to atmospheric density and elasticity coefficient, and also follows certain laws. Most of these laws are determined through experiments. . The specific formulas and curves will not be repeated here. In short, the air resistance is proportional to the square of the speed and proportional to the elastic coefficient.
The calculation process is relatively old-fashioned. During the ascent process, calculate the resistance and height of the bullet for every change of 1m/s (mobile phone, rifle bullet) or 3m/s (high machine bullet) in the ascent process. The air resistance can be considered unchanged within the speed interval, so it can be calculated with excel to list a table. In order to save time, the following results are directly displayed: when the speed drops to 0, the maximum height that can be reached is 1046.8 For meters, 2212.6 meters and 4748.5 meters, the required time is 11.6 seconds, 16.9 seconds and 25.5 seconds respectively. The descent process of
is divided into two situations, one is that the bullet is facing down, and the other is that the bullet is facing up. At this time, because the speed of the bullet is not so fast, the air drag coefficient can be considered unchanged throughout the process, and we change it to every altitude. Down a few meters,Just calculate the air resistance and velocity of the bullet, so that two curves are obtained:
with the warhead down
with the warhead down
Obviously, the resistance is low when the warhead falls to the ground, and it falls to the ground. The speed is high, the landing speed of the three bullets reached 83.38, 134.53 and 194.36 m/s respectively. When the warhead landed upward, the resistance was great, and the landing speed dropped to 48.07, 58.57, and 88.45 m/s.
In addition, we can also calculate the specific kinetic energy, that is, the kinetic energy per square centimeter. According to the Ministry of Public Security's definition of a simulated gun, the muzzle specific kinetic energy is less than 1.8 joules/square centimeter, and it is considered a gun if it exceeds this. When the warhead is facing down, the specific kinetic energy of the three warheads is 40.7, 134.5, and 727.5 Joules/cm², respectively, and when the warhead is facing up, they are 14.4, 28, and 150.7 Joules/cm², respectively. So can the three of them kill people? Let's look at them separately.
9X19 pistol bullet: If the bullet heads up and hits a person, it is equivalent to hitting a stationary bullet while driving 180 kilometers per hour. If it is headed down, it is equivalent to hitting a bullet while riding a high-speed rail, which may not be able to It's terrible, but it may be hurt, or it hurts like "Mythbusters" said!
Imagine sitting on a high-speed rail and hitting an object the size of a bullet
7.62X39 mm assault rifle bullet: Landing with the bullet facing up is equivalent to hitting a bullet while driving 210 kilometers per hour, while sitting down is equivalent to sitting When the maglev of 484 kilometers per hour hits a bullet, if the latter is the case, it is indeed possible to kill people. As for the 14.5X114 high machine ammunition, no matter what posture it falls on, it will be killed or injured. If it falls head to the ground, its specific kinetic energy is even equivalent to the specific kinetic energy of the muzzle of a pistol, and it can definitely kill people.
It can be seen that the lethality of different types of bullets varies greatly after landing. This time, the Taliban soldiers are likely to use 7.62 millimeter mid-power bullets. Even if they are fired vertically upwards, they will have considerable lethality when they fall.Coupled with a certain launch angle, the power will be greater, and it is not uncommon to cause 17 deaths.
#Afghan Taliban asks soldiers to stop firing shots in the sky# #Taliban soldiers fired shots to celebrate 17 deaths and 41 injuries#
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