Three point charges are located away from a dot. charge 1 is 3 cm north of the dot and is 2.1 nC. Charge 2 is 5 cm east of the dot and is -5nC. Charge 3 is -10nC and is located 45 degrees northeast and 5.831 cm away from the dot. What is the net electric field at the position of the dot?

Answer 1

This is simple vector addition using kq/r^2 as the magnitude. The NE charge will need to be split into its components sin 45 and cos45 times the magnitude. And watch your signs, the N and NE have OPPOSITE signs and will act against each other.