posted by Jen .
Two point charges are placed on the x axis as follows: Charge q1= +4.00 nC is located at x= 0.200 m, and charge q2= +5.00nC is at x= -0.300 m. What are the magnitude and direction of the net force exerted by these two charges on a negative point charge q3= -0.600 nC placed at the origin?
Use Coulomb's law and add the two forces on q3 as vectors. Charges q1 and q2 pull q3 in opposite directions, because they are on opposite sides of q3. .