Albert Einstein also said that everything around was a real miracle, and he was right. In everyday everyday life, we often stop noticing natural phenomena, taking them for granted. Gravity could not escape a similar fate . Everyone knows a funny story related to its discovery: it’s enough to recall Newton and the apple that fell on the scientist’s head.
The idea of what gravity is, a person receives in childhood. So, a horizontally thrown snowball gradually changes its path, leaning down, and falls to the ground. Sleds are rolling downhill. Raindrops tend to the ground, etc. Yes, and bruises with bruises from falls - gravity is also “to blame” on them.
Earth, like any other planet, attracts any material bodies that fall into the zone of gravity. As you move away from the attracting object, the intensity of the impact decreases. Since the snowball is attracted to the ground, and not the earth to a horizontally flying snowball, it can be assumed that the force depends on body weight. Another question: why is the snow trajectory a curve, and immediately after the throw does not immediately fall? Obviously, gravity is characterized by intensity, has a certain value that can be measured, which I. Newton did.
He wondered why objects of different masses, falling from the same height, reach the surface at different times. To clarify this, the scientist did a simple experiment: placed several objects of various masses in a glass tube, for example, a lead ball and the lightest fluff. He created a vacuum in the tube itself and turned it 180 degrees. As a result, all the objects that were at the bottom found themselves at the top and, under the influence of gravity, rushed down. Watching the fall, Newton found that all objects reached the bottom at the same time. This allowed us to argue that the force of gravity has the same effect on all objects, regardless of their mass.
However, life experience indicates the opposite: the fluff will fall later than a lead ball. In fact, this is easily explained, because the difference is not only in the mass, but also in the presence of atmospheric air that inhibits the fall. This resistance depends on the density of the body, its shape and, as a consequence, its height. Under ideal conditions, when the field’s propagation zone is large enough, the distance from the massive attracting object (planet) tends to infinity, and there is no medium affecting the movement between falling objects and the surface, the fall will occur with the same acceleration. At the same time, if we take into account the fact that gravity is the force due to which the bodies are mutually attracted, then with infinite distance (ideal theoretical conditions) the mass of the falling object will also affect the fall. In other words, although the planet has an effect of F = m * g on the fluff and ball, they, in turn, also attract the planet. But since the masses are not comparable, then this "additional" force in the calculations can be neglected.
The action of gravity tells all objects the same acceleration, at the surface of the Earth it is 9.81 m / s². As already indicated, the force weakens with distance, which was confirmed by measurements at the upper boundary of the atmosphere - there the acceleration is less than 9 m / s². The acceleration of gravity depends on the mass of the object, thus, on the Sun, this value reaches 273 m / s².
After conducting his experiments, Newton determined that gravity is the product of body mass and acceleration, and formulated his famous formula F = m * g.
It should be noted that, based on this formula, it follows: g = F / m. This gives the dimension for accelerating gravity - "Newton / kilogram". This designation is equivalent to “m / s²”.