Question

Q has a negative charge and is equal to -7.5. It's equidistant from both q1 and q2. q1 is 10 cm away from Q and q2 is 10 cm away from Q. In order for static equilibrium to occur, what charge will q1 and q2 have to be?

I was thinking that it would be positive 7.5 because both sides would be equal to zero. Is that right?

Answer 1

You have to give the directions. Are they on the same side of Q or opposite sides? If opposite then if they are both +something their field is 0 at the origin and if they are both - anything they also cancel

Answer 2

Note they just have to have the same magnitude so their E cancels. They do not have to be 7.5