Hello !

Two protons are subject to two forces; the nuclear force and the electrostatic force . When they are very close together the nuclear force is dominant and when they are far apart it is the electrostatic force which is dominant.

For the charges of the protons the formula for the force reduces to

F = α/s²

where s is the separation distance of the proton centers and α is equal to 2.3103×10-28

Hope it helps !