The electron charge is called the Elementary Charge, given by:
The Eletrostatic Force bewteen two changes is giver by Coulomb Law:
Substituing the unknowns, we have:
![F= \frac{(1.6*10^{-19})^2}{(10^{-8})^2} \\ F=(1.6*10^{-11})^2 \\ \boxed {F=2.56*10^{-22}N}](https://tex.z-dn.net/?f=F%3D%20%5Cfrac%7B%281.6%2A10%5E%7B-19%7D%29%5E2%7D%7B%2810%5E%7B-8%7D%29%5E2%7D%20%20%5C%5C%20F%3D%281.6%2A10%5E%7B-11%7D%29%5E2%20%20%5C%5C%20%5Cboxed%20%7BF%3D2.56%2A10%5E%7B-22%7DN%7D)
If you notice any mistake in my english, please let me know, because i am not native.
It will take a total of 15 minutes i believe. t = d/r
t = 5mi/20mph = .25hr
60 min = 1 hr
.25*60 min = 15 minutes it wil take him