introduction

Gravity is the natural force that attracts objects with mass towards each other. It's what keeps us anchored to the Earth and planets in orbit around the Sun. It's a fundamental concept in physics, explored by Newton and further refined by Einstein's theory of general relativity. Understanding gravity is essential for explaining motion, celestial mechanics, and the behavior of the universe.

types

**There are two main types of gravity commonly discussed in physics.

1. Newtonian Gravity: This is the classical description of gravity formulated by Sir Isaac Newton. It describes gravity as a force of attraction between two objects with mass. According to this theory, the force of gravity weakens with distance according to the inverse square law, and it's the same for all objects with mass. It is highly accurate for everyday situations and most astronomical observations.

2. Einstein's General Relativity: Albert Einstein's theory of general relativity provides a more comprehensive and accurate description of gravity. It conceptualizes gravity as the warping of spacetime caused by mass and energy. Objects with mass follow curved paths in this warped spacetime, which we perceive as gravitational attraction. General relativity has been confirmed through various experiments and is essential for understanding phenomena like black holes and the bending of light by gravity.

**Additionally, there are other types of gravity or related concepts in specialized contexts, such as:

1.Microgravity: The condition of near-weightlessness experienced by objects in freefall, often encountered in space or during parabolic flight.

2.Antigravity: A hypothetical concept often explored in science fiction, where gravity is countered or nullified in some way.

3.Negative Gravity: Another speculative idea where gravity could repel rather than attract, which has not been observed in nature.

Gravitational Force

Newton’s Law of Universal Gravitation is used to explain gravitational force. Gravitational Force is a type of Non-contact force, the gravitational force is a force in nature that is always attractive and conservative. Gravitational Force is defined as the force of attraction experienced by two or more objects in contact. Gravitational force is determined by the formula obtained from Newton’s Universal Law of Attraction, known as the Gravitational Force Formula. Our environment is surrounded by gravity. It determines how much we weigh and how far a basketball will bounce before hitting the ground when it is thrown. The force the Earth applies to you is equal to the gravitational force on Earth. The gravitational force is equal to your weight while you are at rest on or near the Earth’s surface. Also, the presence of a gravitational field is required in the heat transfer through natural convection.

What is Gravitational Force?

The gravitational force is a force that attracts any two objects in the universe, whether they have equal masses or not. Furthermore, Newton’s Universal Law of Gravitation states that everything, including you, pulls every other object in the universe. The unit of gravitational force is Newtons, denoted as N.

The study of gravitation has benefited a lot from the contributions of many well-known scientists. Early in the 17th century, Italian astronomer Galileo Galilei discovered that all objects accelerate uniformly toward the center of the Earth. In his groundbreaking study from 1687, English mathematician Isaac Newton made the first discovery of gravitational laws.

Gravitation is considered a fundamental force as its influence on any object can be observed readily. Thus, Gravitational force acts on every object that has mass. So gravitational force is a fundamental force. Since there is no touch between the objects, the gravitational force is non-contact. Since it is focused at the center of the orbit in which the object moves, it is centripetal. It is responsible for keeping the body’s orbit. A tug that is directed away from the center is experienced by the rotating body. The centrifugal force is what causes this pulling. Of all the basic forces, the gravitational force is the weakest.

Newton’s Law of Gravitation

Newton’s Law of Gravitation or Newton’s Law of Universal Gravitation (or Universal Laws of Gravitation) is the Law that leads to the further study of Gravitation and states that all the objects in the universe having any masses always attract each other with a force of attraction. This force of attraction is called the Gravitational Force (F) which is,

• Directly proportional to the product of the masses (m1 and m2) of the two objects in contact with other, and
• Inversely proportional to the square of the distance (r) between their centers.

The expression or the relation for the above-stated law is given by the gravitational force formula, discussed below:

Gravitational Force Formula

The Law of Gravitation gives the Gravitational Force (F) between two bodies of masses (m1 and m2) at a distance r, apart from their centers, is given as:

F ∝ m1m2

and 

F ∝ 1/r2

Now, combining the above two relations as,

F ∝ m1m2 / r2

 

or 

F = Gm1m2 / r2

where G is the proportionality constant known as Gravitational Constant (= 6.67 ×10−11N⋅ m2/kg2). 

Unit of Gravitational Force

• The SI unit of Gravitational Force is Newton (N).
• The Dimensional Formula of Gravitational Force is [M1L1T-2].

Properties of Gravitational Force

Here are some important characteristic features of Gravitational Force,

• Gravitational forces are always attractive and the weakest of all the fundamental forces.
• It is a type of Non-Contact Force, as it does not require any physical contact or touch to be experienced by a system of objects.
• Gravitational Force is a Long-range force and does not require any medium.
• The Gravitational Force value at the surface of the Earth is constant.