Thursday, December 16, 2010

Basic Forces in Nature


Basic Forces in Nature
Following Four Basic Forces operate in all natural processes:
  1. Gravitation Forces
  2. Weak Force
  3. Electromagnetic Force
  4. Strong Forces
1. Gravitation Forces
  • It is the force of attraction between two masses.
  • It is always attractive in nature; hence sometimes it is taken with negative sign.
  • It is a long range force, i.e., it can extend up to infinity.
  • It follows inverse square law i.e., F ∞ 1 / r2.
  • It is assumed to be created by a particle called gravitation.
  • It is central force and hence, it is conservative in nature.
  • It is the weakest force.
2. Weak Force in Physics
a) It is the force associated with beta - decay in radioactivity.
b) During beta - decay, following reaction takes place.

Neutron Beta Particle
or Electron
 Proton Antineutrino
Since, neutrino is a chargeless - massless particle, therefore during beta - decay, the electron and antineutrino interact with each other through very weak forces.
c) Moreover, the leptons interact with Leptons, Baryons or Mesons through these weak forces.
3. Electromagnetic Force Physics
a) Force between two static charges is called electrostatic force.
b) A moving charge produces both magnetic and electric fields.
The charged particle moving in magnetic field experiences a force called electromagnetic force comprising of electrostatic as well as magnetic forces.
c) Electromagnetic force bears following properties:
  1. It may be attractive or repulsive in nature.
  2. It is created due to exchange of photons.
  3. It is long range force.
  4. It is 1011 time stronger than weak forces and 1036 times stronger than the gravitational force.
  5. It is central and conservative force.
4. Strong Forces (Nuclear Force)
  1. It is the force of nuclear origin.
  2. It is basically attractive in nature.
  3. It is short range force and is operative only inside the nucleus (i.e., for distance = 10-14 m)
  4. They are produced by the exchange of mesons between the nucleons (neutron & proton).
  5. It is not a central force.
  6. It is the strongest force acting in nature. The relative strengths of the gravitational force, the weak force, the electromagnetic force and the strong nuclear force are :

    Fg : Fw : Fe : Fn :: 1 : 1025 : 1036 : 1038

Basic Forces in Nature


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