Free fall is the movement of bodies under the influence of gravity. If a separate object falls in the air, then the resistance of the environment also begins to act on it, so such a movement cannot be considered free fall, which is possible only in a vacuum.
The value that shows the speed of this indicator is called the acceleration of free fall. It is directed vertically downward and is the same for all bodies (regardless of their mass, but in the absence of a resistance force). 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.
It is quite easy to make sure that free fall is characterized by precisely such regularities using 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 soldered, and a crane is placed on the other. If you put a pellet, a cork and a feather into it, and then quickly turn this tube over, you can see a certainfeature - all bodies reach the bottom at different times. The pellet will fall first, then the cork, and the last will be the feather. It is worth noting that bodies fall in this way only when there is air in the tube. If you pump it out with a special pump, and then turn Newton's tube over again, you can be sure that all three objects will fall at the same time. This is free fall.
It is worth noting that this phenomenon has certain features depending on the geographical location of the area. Thus, 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 such a difference be explained?
Among the main reasons for a slight deviation of the digital values of acceleration during free fall, one can name the daily rotation of the planet around its axis, some change in its spherical shape, as well as the unequal distribution of terrestrial rocks.
Besides this, the height of the body above the surface of the planet has a certain influence. If we do not take into account the rotation of the Earth, with its increase, the acceleration of gravity decreases slightly. It should be noted that for a small height this parameter is considered constant, and the bodies are characterized by uniformly accelerated motion.
I must say that there is a record for a long jump from the stratosphere. It was installed by Austrian skydiver Felix Baumgartner. He overcame a height that was more than38 kilometers above the Earth's surface. Now on account of this daredevil the highest parachute jump, as well as the maximum speed of a free fall of a person, which exceeded the speed of sound. After spending about 4 minutes on his flight, Felix opened his parachute and made a safe landing on the ground without any problems, easily setting a new record.
