## Discovering Gravity:

There is a popular story that Newton was sitting under an apple tree when an apple fell on his head, which triggered the idea of the Universal Law of gravitation. However, the apple incident is only a minor part of the effort and the inspiration that lead to the discovery of gravity, because in reality what he discovered was that there is an external force is required to change the speed or direction of a moving object, and further experimentation led to the theories of gravity.

Isaac Newton is credited for discovering gravity. This concept of gravity wasn't well known until Newton's idea was published in a book in 1687.

Newton came up with the theory of gravity, when he observed an apple fall from a tree, and Newton began to think "the apple accelerated, since its velocity changes from zero as it is hanging on the tree and moves towards the ground, by Newton's 2nd law there must be a force that acts on the apple to cause this acceleration." He called this force "gravity" and associated acceleration with gravity. Newton thought that if the force of gravity could reach the top of the tree, then it might go even further, it might even reach all the way to the orbit of the moon and developed the theory of universal gravitation.

Newton publicized this theory in the 1680s, it is called the Law of Universal Gravitation. The Law of Universal Gravitation states "every object in the Universe attracts every other object with a force directed along the line of centers for the two objects that is proportional to the product of their masses and inversely proportional to the square of the separation between the two objects." It set forth the idea that gravity was a predictable force that acts on all matter, his theory states that each particle of matter attracts other particles.

Gravity is affected by a many different things, therefore the amount of gravity varies in different places on Earth. The factors that gravity depends on are: mass, distance and placement. The mass of an object determines the overall gravity of the object, it is also affected by the distance between two objects as the closer they are the stronger the gravitational pull. As the distance between two objects gets larger; the gravitational force becomes smaller, it would never get to zero just too small for the matter.

An example of gravity is that astronauts in space are weightless because they are falling around the Earth, not because there is no gravity in space but rather because there is gravity everywhere,

To calculate gravitational force, the standard formula is:

Gravitational force = G x m1 x m2 / d^2

Where g is gravitational constant, m1 and m2 are the masses of two objects that you are calculating the force force and d is the distance between the centers of gravity of the two masses.

Newton came up with the theory of gravity, when he observed an apple fall from a tree, and Newton began to think "the apple accelerated, since its velocity changes from zero as it is hanging on the tree and moves towards the ground, by Newton's 2nd law there must be a force that acts on the apple to cause this acceleration." He called this force "gravity" and associated acceleration with gravity. Newton thought that if the force of gravity could reach the top of the tree, then it might go even further, it might even reach all the way to the orbit of the moon and developed the theory of universal gravitation.

Newton publicized this theory in the 1680s, it is called the Law of Universal Gravitation. The Law of Universal Gravitation states "every object in the Universe attracts every other object with a force directed along the line of centers for the two objects that is proportional to the product of their masses and inversely proportional to the square of the separation between the two objects." It set forth the idea that gravity was a predictable force that acts on all matter, his theory states that each particle of matter attracts other particles.

Gravity is affected by a many different things, therefore the amount of gravity varies in different places on Earth. The factors that gravity depends on are: mass, distance and placement. The mass of an object determines the overall gravity of the object, it is also affected by the distance between two objects as the closer they are the stronger the gravitational pull. As the distance between two objects gets larger; the gravitational force becomes smaller, it would never get to zero just too small for the matter.

An example of gravity is that astronauts in space are weightless because they are falling around the Earth, not because there is no gravity in space but rather because there is gravity everywhere,

To calculate gravitational force, the standard formula is:

Gravitational force = G x m1 x m2 / d^2

Where g is gravitational constant, m1 and m2 are the masses of two objects that you are calculating the force force and d is the distance between the centers of gravity of the two masses.