Constants

$k=\frac{1}{4\pi {\epsilon }_0}=8.9875\times 10^{9}N{m}^2{C}^{-2}$

$$\epsilon =8.85\times 10^{-12}{C}^2{m}^{-1}{m}^2$$ $$q_e=-1.602\times 10^{-19}C$$ $${\mu }_0=4\pi \times 10^{-7}$$ $$c=3.00\times 10^{8}m{s}^{-1}$$