Gravitational force and Newton law

 

Gravity

The force of gravity, or gravitational force, pulls objects with mass toward each other. We often think about the force of gravity on Earth. This force is what keeps your body on the ground. But any object with mass exerts a gravitational force on all other objects with mass. For example, there is a gravitational force between you and every object around you! The gravitational force between two objects is larger when the masses of the objects are larger. That’s why you can feel the gravitational force between you and Earth, but the force between you and objects with smaller masses is too weak to feel. The gravitational force between two objects also depends on the distance between their centers (Khan Academy).

What Is Gravitational Force?

Gravitation is a study of the interaction between two masses in the world. Out of the two masses, the heavier one is called source mass, and the lighter one is called test mass.

Gravitational force is a central force that depends only on the position of the test mass from the source mass and always acts along the line joining the centers of the two masses. 

F(r) = F(r)r

The interaction between the two masses and their relativistic effects is understood. 

(byjus.com).

Newton Law

This force of attraction was first observed by Sir Isaac Newton and was presented as Newton’s law of gravitation in the year 1680. However, gravitation can generally exist in two main instances.

1. Gravitation may be the attraction of objects to the earth.

For example,

If a body (ball) is thrown upwards, it reaches a certain height and falls downwards because of the gravity of the earth.

2. Gravitation may be the attraction of objects to outer space.

For example,

The force of attraction between other planets and the sun.