On the other hand, Coulomb's law states that an electron and a proton are mutually attractive. Hence, the repulsive force between an electron and a proton should be negligible compared with the attractive force. In this paper, as an electron and a proton approach an object with an equal velocity v, the proton temperature Tp is about 1836 times the electron temperature Te. The isothermal Eq. 19 cannot be used. Hence, applying Eq. 17, an electron exerts a force on a proton, where rp is the radius of a proton (𝑟 = 8.42 × 10 m),