Forces In Nature

1.The Gravitational force.[G.F]It is the force of attraction between two objects due to their masses and is governed by Newton’s law of gravitation.The force of attraction between two objects of masses M₁ and M₂ held at a distance r apart is given by
    F= \( \frac{{GM_1 M_2 }} {{r^2 }} \)  
Where G(= \( 6.66 \times 10^{11} Nm^2 kg^{ - 2} \))is called universal constant of gravitation.

The gravitational force has following properties:
i) it obeys inverse square law.
(ii)It is always attractive in nature
(iii)It is a long range force i.e., it  extends up to infinity
(iv)The gravition is the field practice of gravitational force
(v)It is the weakest force operating in nature
(vi)It is a central force and hence a conservative force

2.The weak force.The leptons are class of elementary particles and include electrons,muons,neutrinos and their antiparticles.The weak force accounts for interaction between leptons and another lepton,between a lepton and meson and interaction.In \( \beta \)-decay ,a neutron inside the nucleus changes into a proton by emmiting an electron and an unchanged particle,called 
antineutrino \( (\overrightarrow v ) \) .The \(\beta\)-decay may be represented as below:
                \( {}_0n^1 \to {}_1H^1 + {}_{ - 1}e^0 + \overline v \)
During the weak interaction, two particles are in contact or exactly overlap each other

The weak force has the following properties:
(i)The weak forces are short range forces(\( \approx 10^{ - 15} m \))
(ii)The weak forces are about 10²⁵  times stronger than the gravitational forces.
(iii)In a weak interaction,neutrino acts as the field particle.