what is gravity. under newton theory.

We don't really know. We can define what it is as a field of influence, because we know how it operates in the universe. And some scientists think that it is made up of particles called gravitons which travel at the speed of light. However, if we are to be honest, we do not know what gravity "is" in any fundamental way - we only know how it behaves.
Here is what we do know...

Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe. Sir Isaac Newton (1642 -- 1727) discovered that a force is required to change the speed or direction of movement of an object. He also realized that the force called "gravity" must make an apple fall from a tree, or humans and animals live on the surface of our spinning planet without being flung off. Furthermore, he deduced that gravity forces exist between all objects.
Newton's "law" of gravity is a mathematical description of the way bodies are observed to attract one another, based on many scientific experiments and observations. The gravitational equation says that the force of gravity is proportional to the product of the two masses (m₁ and m₂), and inversely proportional to the square of the distance (r) between their centers of mass. Mathematically speaking,


F=Gm₁m₂ / r²,
where G is called the Gravitational Constant. It has a value of 6.6726 x 10^-11 m³ kg^-1 s^-2.

The effect of gravity extends from each object out into space in all directions, and for an infinite distance. However, the strength of the gravitational force reduces quickly with distance. Humans are never aware of the Sun's gravity pulling them, because the pull is so small at the distance between the Earth and Sun. Yet, it is the Sun's gravity that keeps the Earth in its orbit! Neither are we aware of the pull of lunar gravity on our bodies, but the Moon's gravity is responsible for the ocean tides on Earth. newton  theory about gravity.

              

What is gravitational fore?

What is the Gravitational Force? This is NOT a. force of contact Any object on the Earth or at least close to Earth, will experience a gravitational force. For example, when one shoots a basketball, the force of gravity acts to pull the ball back to the floor.

How is the Gravitational Force related to what we call weight ? The gravitational force on Earth is equal to the force the Earth exerts on you. At rest, on or near the surface of the Earth, the gravitational force equals your weight. On a different astronomical body like Venus or the Moon, the acceleration of gravity is different than on Earth, so if you were to stand on a scale, it would show you that you weigh a different amount than on Earth.

Your "effective weight" can change, that is, if you are on a scale in an elevator which suddenly moves upward, the scale will suddenly read a different amount. This has to do with the motion of the elevator rather than a change in your mass or the force the Earth is exerting on you. Another example of this is the astronaut in space who is "weightless". The Earth is still exerting a force on the astronaut, but because the space craft is accelerating as well, the astronaut will appear "weightless".

How does one quantify the gravitational force ? The magnitude of the force is mass * |gravitational acceleration|. On Earth, the gravitational acceleration (often written as g) is 9.8 m/s² On the Moon, this value is about 1.6 m/s².


To review: gravitational force  

Is NOT a force of contact . Acts toward the center of mass of an object (for Earth, this is toward the center of the Earth)

it is not my view it is other scientist view like newton, i will write my thinking, just read what was the  other scientist theory then  i will write about kiran gravity.