# Nature of Fundamental Forces

## Nature of Fundamental Forces

If you are asked how many types of forces are there on the earth? You certainly will say, many types.

If we push anything this is a force, when a truck carries or pulls a load this is a force, when a tree is uprooted due to a strom this is a force, when a magnet attracts iron this is a force, when houses are blown away in bomb blasts, it is a type of force, it is a force, when a crane lifts something this is force. If you are given some time, you can prepare a big list of such types of forces.

But do you know the amazing matter? There are only four types of forces in nature, if the forces described above are analyzed, you will find that they are not outside these four types. Fundamental forces are actually only four in number.

These are Gravitational force, Electromagnetic force, Weak nuclear force, and Strong nuclear force.

Gravitational Force

All objects in the universe attract one another by a force due to their mass. This force is called the gravitational force. Due to this gravitational force the stars are revolving within the galaxy or the earth is revolving around the sun and the moon is revolving around the earth. When the force of gravitation of the earth works on us, we call it gravity. This gravity attracts us towards the center of the earth i.e, pulls downwards and due to this pull we feel our weight.

Force of gravitation is an amazing force of physics. An object that has mass attracts another object by the gravitational force. In this chapter, we shall discuss the gravitational force a little bit more in detail.

Electromagnetic Force

We have seen, now and then, that when we comb our hair with a comb it attracts pieces of papers. We have also seen that a magnets attract or repulses another magnet. Though we think that electric and magnetic forces are different in nature, actually the two forces are identical. They only appear in two forms. Only and this electromagnetic force can attract and repulse but the other forces can attract only, cannot repulse. It is so much stronger than gravitational force (1036 times, or trillion trillion trillion times stronger). That the statement is true, you can definitely guess. Because when you comb your hair by a comb and pull a piece of paper by attraction, the whole earth tries to pull the piece of paper by the gravitational force due to its total mass. But the small amount of electricity in your comb defeats the total gravitational pull of the giant earth.

Weak Nuclear Force or Weak Force

It is called weak because it is weaker than the electromagnetic force (approximately trillion times weaker) but not at all weak like the gravitational force. The force of gravitation and the electromagnetic force can act from any distance but this force acts for very small distance (10-18 m). The emission of beta rays or electrons from a radioactive nucleus is due to this weak nuclear force.

Strong Nuclear Force

This is the strongest force of the universe; this is hundred times stronger than the electromagnetic force but this too acts at a very small distance (10-15 m)

We know the nucleus is situated at the centre of the atom and the strong force acting between the protons and the neutrons within the nucleus confines them. Confined due to this strong nuclear force, the nucleus contains an enormous amount of energy. Therefore by the division of a large nucleus or by the addition of small nucleuses a huge amount of energy can be produced due to this force. For this reason a nuclear bomb has so much energy. By this force light and heat is produced in the sun.

According to scientists these four types of forces have the same origin and they are trying to explain all these forces by a single law. Meanwhile, it has become possible to explain the electromagnetic force and the weak nuclear force by a single law. This is a tremendous success of theoretical physics. (Therefore, you can say, forces are of three types: Gravitation, Electro-weak and Nuclear Force. Nobody will say it is wrong). The scientists are trying to unify the other forces too by a single law.

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