Galileo Galilei and uniformly accelerated motion

All bodies in real conditions can not move withconstant speeds, and usually the speed of the body varies with time and in direction, and in magnitude. Such a motion is called uneven. The simplest uneven motion of bodies is a rectilinear uniformly accelerated motion, and a free fall can be considered as a prime example.

The theory of uniformly accelerated motion was developed by Galileo Galilei. It was he who first defined this type of motion, described its laws and proved a number of theorems.

Scientists have studied the motion of physical bodies sincetime immemorial. Long before the birth of Galileo, the foundations of kinematics were laid. Now, to determine the path traveled by the body for some time with a known constant speed, any elementary school student can. It is enough to multiply the speed of the body by the time of movement - and the answer is ready!

Difficulties arose as soon as steelconsider the movement of a body with variable speed, and yet in life it happens almost always. Look at the arrow of the speedometer of the car - it is constantly on the move and shows that the speed of the car changes almost every minute, and even more often. This problem - how to calculate the path of the body with an ever-changing speed - worried the minds of scientists long before Galileo.

After a series of experiments, Galileo showed that the concept of "free fall of the body" is equivalent to the concept of "uniformly accelerated motion."

Today, having ultra-precise measuring devicestime, even a schoolboy will be able to observe the dynamics of the fall. At the time of Galileo, the usual mechanical clock was a rarity, and inaccurate and primitive. Therefore, the scientist had to create a completely new device, with the help of which the problem of all measurements of magnitudes during the fall was solved. Experimenting and changing the conditions of the experiment, making measurements and conclusions, Galileo gradually came to the conclusion that the body, starting at zero speed, moves further, gradually increasing this speed. Translated into the language of mathematics, the uniformly accelerated motion observed by him can be described using the formula a = vt d = (at2) / 2, where v is the velocity, the acceleration of the body is a, d is the distance the body has traveled in time t.

If you observe the fall of bodies and analyze the data of the formula, then you can follow the scientist after the statement:

• the rate of fall with time, elapsed since the beginning of the movement, even visibly increases;

• If the body performs an equally accelerated motion, then the first half of the path will take longer than the rest;

• The longer the body "accelerates", the greater the distance it travels at identical intervals of time.

In addition, Galileo Galilei made anothera rather important conclusion, however, could not be confirmed by its measurements. He found that the acceleration of gravity g is almost the same near the surface of the Earth and is equal to g = 9.8 m / s2. This value characterizes the fall of bodies near the surface of our planet due to the forces of gravity, therefore it is called acceleration of gravity acceleration.

The results of Galileo's studies were the basisfor the later triumphal discoveries of Newton and formed the basis of modern classical mechanics. Much later, Newton showed that the acceleration of the body can be calculated theoretically, using the laws of mechanics discovered by him and the law of universal gravitation.

Another no less important conclusion from the discoveriesGalileo - the acceleration of free fall is completely independent of the mass. This practical conclusion completely contradicted all earlier statements of natural philosophers. After all, they claimed that every thing tends to the center of the universe (and the Earth, in their opinion, this center was) and the more massive the object, the faster it does it.

Of course, Galileo made his conclusions on the basis ofexperiments. But it is unlikely that the scientist conducted the experiments attributed to him, dropping various objects from the "falling" tower in Pisa, ostensibly demonstrating that they would all fall to the surface of the Earth at the same time. We can only confidently say that Galileo knew for sure: heavier objects will fall to the ground faster because of the air resistance acting on them. But people tend to invent fables.