Coulomb’s force of repulsion between two protons is given by –

Where,

q₁ and q₂ = are the charges

k = proportionality constant = 9×10⁹

r= distance between the charges

Now, gravitational force,

Where,

G = universal gravitation constant =

m_{1 =mass} of first object

m₂ = mass of second object

r = distance between the objects

Now, we know that-

Charge of the proton, q = 1.6×10^-19 C

Mass of the proton = 1.67×10^-27 kg

Let r be the distance between two protons

Coulomb force of repulsion between the two protons is given by –

fe=14π∈0×q2r2=9×109× (1.6)2×10-38r2

Gravitational force between the protons is given by –

Dividing the equations -