$\alpha$ Day Problem 1

If 2 elementary charged particles interact with each other electromagnetically. Also, it is given that interaction has some strength, then find the number/factor characterizing this strength.

Details and Assumptions

Planck's constant(h) = 6.626 X ${10} ^{-24}$ Js [You may use reduced constant as well]

Speed of light(c) = 3 X ${10}^{8}$ m ${s}^{-1}$

Permittivity factor = 9 X ${10}^{9}$ $N{m}^{2}{C}^{-2}$

Round your answer to 2 decimal places and in the form (decimal E n)