Question: what is the gravitational force between two protons?
Answer: Gravitational force between two objects is given by F=G(m1)(m2)/(r^2). G is the universal gravitational constant with the value of 6.67*10^-11. m is the rest mass of a proton, at 1.67*10^-27 kg. Electrostatic force between two charges is given by F=(q1)(q2)/(4πεο r^2).