e24πϵ0m2r2\frac{e^{2}}{4 \pi \epsilon_{0} m^{2} r^{2}}4πϵ0m2r2e2
e24πϵ0r2\frac{e^{2}}{4 \pi \epsilon_{0} r^{2}}4πϵ0r2e2
e24πϵ0m2r\frac{e^{2}}{4 \pi \epsilon_{0} m^{2} r}4πϵ0m2re2
e24πϵ0mr2\frac{e^{2}}{4 \pi \epsilon_{0} m r^{2}}4πϵ0mr2e2
e24πϵ0mr\frac{e^{2}}{4 \pi \epsilon_{0} m r}4πϵ0mre2