Are speed and position both scalar units

The diagram shows four locations in the electric field of a positive point charge m. at which location is the electric potential the greatest.

Two point charges are separated by a certain distance. how does the strength of the electric field produced by the first charge

Athird point charge q3 is now positioned halfway between q1 and q2. the net force on q2 now has a magnitude of f2,net = 5.861 n and points away from q1 and q3. what is the value (sign and magnitude) of the charge q3?