Question

An electron and a proton have charges of equal magnitude but of opposite sign. The magnitude of the charge is 1.6 x 10-19 C. If the electron and proton in are separated by a distance of 5 x 10-11 m, what is the magnitude of the electrostatic force exerted on the electron by the proton?
Give your answer in nano Newtons. ( Divide your answer by 10-9)

Hello, I would like to know how to do this, do I use the F=kq1q2/ r^2? And would it look something like this?
F= 9 x 10^9 (1.6 x 10^-19)(1.6 x 10^-19)/ 5^2 because this is what I did and got 9.2 x 10^-29, but when I plugged it in I got it wrong. How to I do this problem and place it in nano Newtons, do I divide F= 9 x 10^9 (1.6 x 10^-19)(1.6 x 10^-19) by 10^2? I got 2.3 x 10^-29. Please tell me what I'm doing wrong.

Answer 1

the distance is not 5m
(9 * 10^9)(1.6 * 10^-19)(-1.6 * 10^-19) / (5 * 10^-11)^2
= -9.216 * 10^-8
= -92.16 nJ