Physical World: Definition of Physical World, What Are the Fundamental Forces of Nature (For CBSE, ICSE, IAS, NET, NRA 2022)

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  • Physics is the study of matter, basic principles, and laws of nature along with their manifestations.
  • The physical world is the only world there is, or the only world that is real. The study of physics is mainly involved in the explanations of the diverse phenomena of its concepts.
  • Traditionally, materialism was a thesis about objects-only. bodies exist, the only things that exist are material things.
  • World contains nothing but physical entities.

Definition of Physical World

  • The physical world is referred to as the complexity in nature and solving its own complexities will give us new insights into this physical world.
  • It is referred to as the analysis of nature conducted in order to understand how the world around us performs.

What Are the Fundamental Forces of Nature?

  • Fundamental force, also called fundamental interaction, in physics, any of the four basic forces — gravitational, electromagnetic, strong, and weak — that govern how objects or particles interact and how certain particles decay.
  • All the known forces of nature can be traced to these fundamental forces.
  • In this diverse world, the fundamental forces which govern the phenomena occurring in it are:

Gravitational Force

  • The gravitational force on Earth is equal to the force the Earth exerts on you
  • It is a universal force that exists which is of mutual attraction between any two objects by virtue of their masses.
  • At rest, on or near the surface of the Earth, the gravitational force equals your weight.

Electromagnetic Force

Electromagnetic Force
  • The electromagnetic force is one of the four fundamental forces.
  • It is the force between charged particles.
  • The electric force acts between all charged particles, whether or not they՚re moving.
  • If charges are in a state of rest, it is given by Coulumb՚s law whereas when they are in motion, they generate a magnetic field, hence the name electromagnetic forces as they are inseparable. They also act over a large distance as seen in the case of gravitational forces without the intervention of any medium
  • The magnetic force acts between moving charged particles. This means that every charged particle gives off an electric field, whether or not it՚s moving

Strong Nuclear Force

This is the Strong Nuclear Force
  • In a nucleus it binds protons and neutrons.
  • The strong nuclear force holds most ordinary matter together because it confines quarks into hadron particles such as the proton and neutron
  • It is the strongest of all the fundamental forces and is charge-independent acting between proton-proton, proton-neutron, or neutron-neutron
  • On a larger scale (about 1 to 3 fm) , it is the force (carried by mesons) that binds protons and neutrons (nucleons) together to form the nucleus of an atom.
  • Weak Nuclear Force – observed only in some nuclear processes. Example – β-decay of a nucleus.
  • It is not as weak as the gravitational force but weaker than electromagnetic and strong nuclear force

What Are the Laws of Conservation in Nature?

The conservation laws in physics are very important when it comes to understanding the subject.

The laws are:

  • Laws of Conservation of Mass
  • Laws of Conservation of Energy
  • Laws of Conservation of Momentum
  • Laws of Conservation of Charge etc.

Laws of Conservation of Mass

Laws of Conservation of Mass

In physics and chemistry, the law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system՚s mass cannot change, so quantity can neither be added nor be removed.

Laws of Conservation of Energy

Laws of Conservation of Energy

In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time.

Laws of Conservation of Momentum

  • One of the most powerful laws in physics is the law of momentum conservation.
  • For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision.

Laws of Conservation of Charge

Charge is neither created nor destroyed, it can only be transferred from one system to another.

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