1. The problem statement, all variables and given/known data Three charges are set in the plane of the page so that they form the vertices of a right triangle of lengths a = 3 meters, b = 4 meters, and c = 5 meters. The charges |Q1| = 2.40 10^-3 C and |Q2| = 1.80 10^-3 C have unknown sign. Charge q = -4. 10^-4 C has a total electric force F directed upward due to the other two charges. Determine the magnitude of the electric field at the position of q due to the other two charges. 2. Relevant equations k = 9 × 109 N m2/C2 E=kq/d^2 3. The attempt at a solution I know that the charges Q1 and Q2 are negative, thus the electric field is going towards them, but I'm not sure what to do after this, any help would be appreciated.