It is known that the planet Earth attracts any body to its core with the help of the so-called gravitational field. This means that the greater the distance between the body and the surface of our planet, the more force the Earth acts on it, and the stronger the gravity.
On the body, falling vertically down, stillthe above-mentioned force, due to the action of which the body will certainly fall down. It remains an open question about what will be its speed at the fall? On the one hand, the object is influenced by air resistance, which is strong enough, on the other - the body is more attracted to the Earth than it is from it further. The first - obviously will be an obstacle and reduce speed, the second - to give acceleration and increase speed. Thus, there is another question about whether it is possible to free fall in terrestrial conditions? Strictly speaking, the free fall of the body is possible only in a vacuum, where there is no interference in the form of resistance to air flows. However, within the framework of modern physics, a free fall of a body is considered to be a vertical movement that does not encounter interference (air resistance can be neglected).
The whole point is that to create conditions whereThe falling object is not affected by other forces, in particular, the same air, can only be artificially. It has been experimentally proved that the rate of free fall of a body in a vacuum is always equal to the same number, regardless of the weight of the body. This movement has received the name equally accelerated. For the first time it was described by the famous physicist and astronomer Galileo Galilei more than 4 centuries ago. The relevance of such conclusions has not lost its power to this day.
Как уже было сказано, свободное падение тела в the framework of everyday life is a conditional and not quite correct name. In fact, the speed of free fall of any body is uneven. The body moves with acceleration, as a result of which such a motion is described as a special case uniformly accelerated motion. In other words, every second the speed of the body will bechange. With this reservation in mind, one can find the rate of free fall of the body. If we do not attach the acceleration object (that is, we do not drop it, but simply drop it from the height), then its initial velocity will be zero: Vo = 0. With every second the speed will increase in proportion to the elapsed time and acceleration: gt.
It is important to comment on the input of the variable g.This is the acceleration of gravity. Earlier, we already noted the presence of acceleration in the fall of the body under normal conditions, i.e. in the presence of air and under the influence of gravity. Any body falls to the Earth with an acceleration equal to 9.8 m / s2, regardless of its mass.
Now, bearing in mind this reservation, we derive a formula that will help calculate the rate of free fall of the body:
V = Vo + gt.
That is, to the initial speed (if we attachedher body by throwing, pushing or otherwise manipulating), add the product of the acceleration of free fall by the number of seconds that it took the body to reach the surface. If the initial velocity is zero, the formula takes the form:
V = gt.
That is simply the product of the acceleration of freefall for a time.
Similarly, knowing the speed of free falling of the object, you can deduce the time of its movement or the initial speed.
It is also necessary to distinguish the formula for countingthe velocity of the body cast at an angle to the horizon, since in this case forces will act that gradually slow the speed of movement of the abandoned object.
In the case considered by us, only gravity and airflow resistance act on the body, which, by and large, does not affect the speed change.
