free fall - this is the motion of bodies under the action of gravity.If a particular item falls through the air, then it begins to act even environmental resistance and, therefore, such movement can not be regarded as a free fall, which is possible only in a vacuum.
values which shows the rate of this index is called the acceleration of free fall.It is directed vertically downwards and is the same for all bodies (regardless of their weight, but in the absence of forces of resistance).This pattern is reflected in the law, which was installed by Galileo Galilei: all bodies are close to the ground with the same acceleration, reaching the surface at the same time, if they do not act extraneous factors.
Make sure that the free fall is characterized by such laws, quite easily with the help of the tube Newton (the so-called stroboscopic method).This glass tube whose length is up to 1 meter.One of its ends sealed, placed on another crane.If she put pellet, cap and a feather, and then quickly flip the tube, you can see a certain feature - all reach the bottom of the body at different times.The first pellet fall, after it - cork, the latter would be a feather.It should be noted that the body thus fall only when there is air in the tube.If it were applied to extort special, and then again to turn the tube Newton, we can make sure that all three objects will fall at the same time.This is a free drop.
It is worth noting that this phenomenon has certain peculiarities depending on the geographical location of the area.So, it is characterized by the highest free fall acceleration at the pole.At the equator, it reaches minimum values - 9.75 m / s2.How can we explain this difference?
Among the main reasons for the slight deviation of digital values of acceleration in free fall, can be called a planet's daily rotation about an axis, a change in its spherical shape, as well as unequal distribution of terrestrial rocks.
addition, certain influence body height above the surface of the planet.If you do not take into account the rotation of the Earth, with its increasing acceleration of gravity is somewhat reduced.It is worth noting that for small height, this parameter is considered constant, and the bodies are characterized by uniformly accelerated motion.
I must say that there is a record concerning skydiving from the stratosphere.It was installed by the Austrian skydiver Felix Baumgartner.He overcame a height of more than 38 kilometers above the Earth's surface.Now, on account of the daredevil highest parachute jump, as well as the maximum speed of the free fall of man, which exceeded the speed of sound.Costs for its flight about 4 minutes, Felix opened his parachute and without problems has made a safe landing on the ground, easily setting a new record.
