 # Gravitational Force

Gravity is the phenomenon that is present in the entire universe. Gravity is a key element that defines and holds the physical connection between space and matter. As we know, gravitational force is one fundamental force present in the universe along with nuclear forces and electromagnetic forces.

Gravity is the force that governs the entire galaxy including planets and stars. In other words, we can say that gravity is the force that acts on all the objects that have mass or energy. Gravity contributes to the weight of the object on the surface of the Earth. Gravity has an infinite range, and the effects of gravity get weaker as the distance between the objects increases. It is denoted by the letter ‘g’.

The concept of gravity was discovered by the famous physicist Sir Isaac Newton in 1687 to explain the motions of the planets and moons. Gravitational Constant was coined by Henry Cavendish after Newton’s death.

## Newton’s Law Of Universal Gravitation and Gravitational Constant

Newton’s Law of Universal Gravitation states that

“Every particle attracts every other particle in the universe with a force that is directly proportional to the product of the masses and inversely proportional to the square of the distance between them”.

The universal gravitation equation is given as

$$F\alpha \frac{m_{1}m_{2}}{r^{2}}\Rightarrow F= \frac{m_{1}m_{2}}{r^{2}}$$

Where,

• F is the gravitational force between bodies
• m1 is the mass of one of the objects
• m2 is the mass of the second object
• r is the distance between the centers of two objects
• G is the universal gravitational constant

### Gravitational Constant

The gravitational constant is also known as the universal gravitational constant, the Cavendish gravitational constant and the Newtonian constant of gravitation. Gravitational constant is denoted by the letter ‘G’.

In classical format, the gravitational constant can be derived from Planck’s length, mass, and time. In the wave format, it comes from the electric force equation.

The universal gravitational constant is given by

G = 6.673 x 10-11 N m2/kg2.

The Gravitational constant has been measured in three ways:

• The measurement with a laboratory balance of the attraction of Earth upon a test mass
• The comparison of the pull of a large natural mass with that of Earth
• The direct measurement of the force between two masses in the laboratory

 Related links Units of measurement Bar magnet Law of conservation of mass Plane mirror

## Frequently Asked Questions on Gravitational Force

### 1. Who discovered the concept of gravity?

Sir Isaac Newton.

### 2. What is gravity?

Gravity is a key element that defines and holds the physical connection between space and matter.

### 3. What is universal gravitational constant?

G = 6.673 x 10-11 N m2/kg2.

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