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# Fundamental Forces in Nature

## Fundamental Forces in Nature Before learning about fundamental forces in nature, we must understand what the term force mean. Forces simply mean a push or pull activity. In our daily life, a force is needed to push, carry, pull or throw objects. We too experience the impact of force in real life. For example when some objects hit us or in a ride like merry go round, where we come up and down. The idea of Force was derived from Aristotle, but his explanations were quite trivial and not up to the mark. The concept of Force was ideally explained by Isaac Newton in the forms of Laws and motion. He also discovered a denotive form of force for the gravitational attraction between two bodies.

In the real world despite gravitational force, we meet different kinds of forces, they are:

• Muscular Force ( Force caused by movement of muscles)
• Friction ( Force between vehicles and roads which help in traveling)
• Forces exerted by strings and ropes ( Helps in retaining size and strength)
• Buoyant Force
• Viscous Force
• Force due to the pressure of a liquid and so on.

In the microscopic world where electrons, protons, and other tiny particles reside, they encounter forces like:

• Electric Force
• Magnetic Force
• Nuclear Force
• Interatomic and intermolecular forces

## Types of Fundamental Forces

To make the study of fundamental forces a bit easier and compact, scientists derived all the forces from four fundamental forces. They are:

• Gravitational Force
• Electromagnetic Force
• Strong Nuclear Force
• Weak Nuclear Force

Let us understand each of the fundamental forces in brief and know how these forces impact our daily lives.

### Gravitational Force Gravitational Force can be defined as the force of attraction between all bodies in the universe. It is a universal force responsible for attraction between two bodies. For example, every object of earth experiences the force of gravity due to earth. If gravity wouldn’t have existed, then we all must be flying in the atmosphere. Einstein stated that the force of gravitation is responsible for the attraction of two bodies having mass Mathematically, the force of gravitation is directly proportional to the product of masses and inversely proportional to the square of the distance between them. It is the weakest of all the fundamental forces.

Example: Suppose there are two bodies A and B, the mass of A is mA and that of B is mB. Let the distance between two bodies be “r”, and then the force of gravitation is given as:

F = kmA mB/ r2

where k is the proportionality constant.

Applications of Gravitational Forces are:

• Gravity keeps everything on Earth from blowing away. It plays an important role in the development of life. Gravity is the force which pulls objects to the surface of Earth
• Without gravity, there won't be any atmosphere, which means no air to breathe
• The solar system is held in stable position with the help of gravitational forces between the sun and other planets.
• The moon revolves around the surface of earth with the virtue of gravitational force only

### Electromagnetic Force Electromagnetic Force is the fundamental force linked with electromagnetic and magnetic fields. It is the force between charged particles. This force is based on Coulomb's law, which states the force of attraction or repulsion between two charges is directly proportional to the product of charges and inversely proportional to the square of the distance between them. Unlike gravitational force, it is of both repulsive and attractive nature. Like charges repel each other and unlike charges attract each other.

Example: There are two charges qA and qB. Let the distance between the charges be “r”, then the electrostatic force of attraction is given as:

F = k qA qB / r2

Where k is constant of proportionality.

Applications of electrostatic force are:

• Electrostatic force is enormously stronger as compared to gravitational force and dominate all the phenomena at atomic and molecular level
• Electrostatic is responsible for stable structures of atoms and their functioning
• It also serves macroscopic forces like tension, friction, normal force and spring forces
• Lightning and electricity are caused by electrostatic forces only

### Strong Nuclear Force The force between protons and neutrons in a nucleus is called strong nuclear force. This is the strongest of fundamental forces. The role of strong nuclear force is to minimize the repulsion between protons and keep the atom stable. If there is repulsion between photons, then, unfortunately, protons may collide with the nucleus and end up destroying the atom. It is of attractive nature. Strong nuclear force is independent of charge and occurs between proton- proton, neutron-proton, and neutron-neutron.

The range of this force is very small nearly 10-15m. The stability of a nucleus is ensured by strong nuclear force.

Note: Nuclear force doesn’t act between electrons.

Applications of strong nuclear force

• Maintains the stability of nuclei
• Used in electrostatics theory

### Weak Nuclear Force Weak nuclear force is defined as the force which causes radioactive processes by carrying out an electron and β emissions. The strength of weak nuclear force lies between those of gravitation and strong nuclear forces. The range of weak nuclear force is very small around the order 10-16 m.

Applications of weak nuclear force

• Used in radiation to cure cancers and tumors
• Helps in generating energy in nuclear plants

## Unification of Forces

Great developments often contribute to the unification of different theories and research areas. Some examples of unification of forces are depicted as follows:

• Newton unified heavenly bodies and planetary bodies under a common law of gravitation
• Experiments carried out by Oersted and Faraday assisted in interlinking of electricity and magnetism. They both proved that electricity and magnetism are inseparable
• Maxwell proved that light is an electromagnetic wave by unifying electromagnetism and optics
• Carlo Rubia and Simon Vander Meer proposed the theory of electro-weak force by unifying electrostatic forces and weak nuclear forces

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