If the coin falls vertically and does not touch the various protrusions on the building, its final speed can reach 241.4 kilometers per hour. If the coin is falling flat, the air resistance during the drop is much greater, and the final speed of the coin may be only 48.3 kilometers per hour. Since the general coin has a tumble rotation when it falls, the falling speed is between the two.
The bullets fired from the pistol are likely to reach speeds of 965 kilometers per hour. In contrast, the speed of coins is much slower, but it is still dangerous, but the danger is not great. It is impossible to kill people. At most, people will feel a tingling spurt, blood flow only (even if it does not bleed, it will also make a slap), and basically there is no danger to life.
According to the laws of physics, objects undergo an accelerated process when doing free fall motion. When moving in the air, the air resistance of the object increases with the increase of the speed, and the object stops accelerating until the upward air resistance is balanced with the downward gravity of the earth. The speed at which the object moves at this time is called the terminal speed.
Whether the coin falls flat or falls vertically, it will reach the terminal speed when it falls. The biggest uncertainty is how it will fall. This has nothing to do with the posture of the coin that you let go, because the process of falling coins is not a steady state process. Any small disturbance will cause its attitude to change, causing it to wobble back and forth, thus increasing the air resistance.
However, if there is no air, there is no air resistance. In this case, the coin will fall in a free fall motion. The acceleration per second is 10 meters. In just 100 seconds, the speed can reach 10,000 per second. The meter, which is 3,600 kilometers per hour, is much larger than the speed of the bullet. In this case, it is very easy to kill a person.