In order to understand planetary motion, Isaac Newton, renowned English physicist, based his studies on Nicolaus Copernicus' heliocentric model.
Then analyzing the motion of the planets, Newton presented an explanation, in which he showed that this motion was based on an attraction between bodies, in this case, between planets.
According to Newton:
• The Sun attracts the planets;
• The Earth attracts the Moon;
• The Earth attracts all the bodies that are close to it.
After analyzing these facts, Newton, in an attempt to summarize these concepts, called them the gravitational force. That is, there is a force that attracts all bodies, whether they are in space or on Earth.
Such forces are vector quantities, because they have magnitude, direction and direction.
The mathematical representation of the law of universal gravitation is:
Where:
F = intensity of the gravitational force
G = universal gravitation constant, whose value is 6.67.10-11 Nm²/kg²
M and m = mass of analyzed bodies
d = distance
Through the equation presented by Isaac Newton, in order to analyze the forces acting on Earth and its surroundings, we must remember that in his Third Law, Newton talks about action and reaction. Based then on this question, we see that the attraction between the bodies must be mutual so that there is a balance between them, that is, the Earth attracts the Moon, but, on the other hand, the Moon also attracts the Earth, with the same intensity, same direction, but with meaning contrary. The same happens with the other bodies already mentioned.
In summary, it can be defined that the gravitational force is the result directly proportional between the product of masses and inversely proportional to the square of the distance between the centers of mass. Such an analysis, of course, must be made for bodies that gravitationally attract each other.
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By Talita A. angels
Graduated in Physics
World Education Team
mechanics - Physics - Brazil School
Would you like to reference this text in a school or academic work? Look:
ANGELS, Talita Alves dos. "Law of Universal Gravitation"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/lei-gravitacao-universal.htm. Accessed on June 27, 2021.
