Two equal charges (Q = +0.80 nC) are situated at the diagonal corners A and B of a square of side x = 1.2 m as shown in the diagram. What is the magnitude of the electric field at point D?
The Attempt at a Solution
First I converted 0.80 nC into C and got 8.0e-10 C.
Using pythagorean's theorum I found 1.7 m as the distance between the two charges.
I then used Coulomb's law as follows:
9e9*8e-10/1.7^2 which gave me 2.5.
Since we want point D, I took the sin(45)2.5 + cos(45)2.5 and came up with 3.52 which was wrong.
Any ideas where I goofed?