On August 20, 2007, a plane flew from Taoyuan, Taiwan to Okinawa, Japan. Shortly after landing, thick smoke suddenly appeared from the right side of the plane. The fire spread quickly and even exploded. Fortunately, the 165 people on board were quickly evacuated within two minutes. And you must not have imagined that the cause of this fire was a screw inserted into the fuel tank because the gasket fell off.
You must know that there are millions of screws inside a large aircraft. So just imagine, what would happen if a nail suddenly fell from a height of 10,000 meters?
I believe that the first reaction of many people is that the screw will do " free fall " movement under the action of gravity. can easily calculate based on the formula. At the moment it falls to the ground, the speed of the nail is as high as 440 meters per second, which is comparable to the speed of the bullet fired by the pistol . Even if it is not shattered to pieces, I am afraid it will be buried in the soil and cannot be found.
Of course, the reality is that the nail is not only affected by downward gravity, but also upward resistance, and the faster it falls, the greater the resistance it encounters. When the gravity and resistance are balanced, the nail will fall at a constant speed. People call the speed at this time "terminal velocity".
Assume that the screw is 4 cm long and weighs 10 grams. Then, based on this complex formula, it can be calculated that the terminal speed of the nail is approximately 22 meters per second. If you end up landing on a brittle object like glass, you're likely to smash it. But fortunately, the skin is elastic. Although it will not be fatal if it falls on it, it will definitely cause some damage. On March 1, 2021, a 3-year-old child was hit by a screw that fell from the 11th floor, and his scalp bled instantly.
But having said that, would such a sophisticated aircraft really drop parts downwards?
The answer is yes. On September 23, 2017, a 4.3-kilogram aircraft part fell from a high altitude in the center of Osaka, Japan, and hit a car. Fortunately, the passengers in the car were not injured. On October 20, 2015, when another plane took off from Cologne Airport in Germany, the skin of the left engine fell on the runway, without the crew knowing it. Finally landed safely at Palma Airport in Spain. Seeing this, you suddenly feel that a small screw is nothing.
Finally, we might as well open our minds a little more. In the distant space station , there are also many screws. What will happen if they fall down?
The answer is far less exciting than imagined, because when these small objects fall into the atmosphere, they will be burned to ashes by friction. It is for this reason that astronauts regularly throw useless items out of the space station.
