Question

A proton and an electron form two corners of an equilateral triangle with sides of length 3

µm. What is the magnitude of their net electric field at the third corner?

Answer 1

$$E_{net}=2E_x=2\frac{kq_e}{a^2}\cos{60}\\ E_{net}=2\frac{(9\cdot10^{9})(1.6\cdot10^{-19})}{(3\cdot10^{-6})^2}\cos{60}=160\frac{N}{C}$$