Answer:
C : 1.4*10^(-11) N.
Explanation:
q_1 = q_2 = 1.6 * 10^(-19)
R^2 = (1)^2 + (4)^2 = 1.7 * 10^(-17) m^2
The coulomb's law is as follows:
F_e = k*q_1*q_2 / R^2
F_e = k*q^2 / R^2
F_e = (9.0*10^9) * (1.6 * 10^(-19))^2 / 1.7 * 10^(-17)
F_e = 1.35 * 10^(-11) N
Hence, answer closes to obtained is option C : 1.4*10^(-11) N.