Free fall is the movement of bodies under the action of gravity. If an individual object falls in the air, then the medium’s resistance also begins to act on it, so this movement cannot be considered a free fall, which is possible only in a vacuum.
The value that shows the speed of this indicator is called the acceleration of gravity. It is directed vertically downward and is the same for all bodies (regardless of their mass, but in the absence of resistance). This pattern is reflected in the law that was established by Galileo Galilei: all bodies approach the earth with the same acceleration, reaching its surface at the same time if they are not affected by extraneous factors.
To make sure that free fall is characterized by just such regularities is quite easy with the help of a Newton tube (the so-called stroboscopic method). This is a glass tube, the length of which reaches 1 meter. One of its ends is sealed, the crane is placed on the other. If you place a pellet, a cork and a feather in it, and then quickly turn this tube over, you can see a certain feature - all bodies reach the bottom at different times. The pellet will fall first, after it the cork, the feather will be the last. It is worth noting that in this way bodies fall only when there is air in the tube. If it is pumped out with a special sediment, and then the Newton’s tube is turned over again, then you can make sure that all three objects will fall simultaneously. This is free fall.
It is worth noting that this phenomenon has certain features depending on the geographical location of the area. So, free fall is characterized by the greatest acceleration at the pole. At the equator, it reaches the smallest values - 9.75 m / s2. How can this difference be explained?
Among the main reasons for the insignificant deviation of the digital values of acceleration during free fall, we can name the daily rotation of the planet around its axis, some change in its spherical shape, as well as the uneven distribution of terrestrial rocks.
In addition, a certain influence is exerted by the height of the body above the surface of the planet. If you do not take into account the rotation of the Earth, with its increase, the acceleration of gravity decreases somewhat. It should be noted that for a small height this parameter is considered constant, and bodies are characterized by uniformly accelerated movement.
I must say that there is a record regarding a long jump from the stratosphere. It was installed by the Austrian skydiver Felix Baumgartner. He overcame a height of more than 38 kilometers above the surface of the Earth. Now, on account of this daredevil, the highest parachute jump, as well as the maximum free fall speed of a person, which exceeded the speed of sound. After spending about 4 minutes on his flight, Felix opened the parachute and made a safe landing on the ground without any problems, easily setting a new record.