Two charges, +4 µC and +16 µC, are fixed 1 m apart, with the second one…

Two charges, +4 µC and +16 µC, are fixed 1 m apart, with the
second one to the right. Find the magnitude and direction of the
net force (in N) on a −9 nC charge when placed at the following
locations.
(a) halfway between the two
Magnitude:____N
Direction:____
(b) half a meter to the left of the +4 µC charge
Magnitude:____N
Direction:____
(c) half a meter above the +16 µC charge in a direction
perpendicular to the line joining the two fixed charges (Assume
this line is the x-axis with the +x-direction
toward the right. Indicate the direction of the force in degrees
counterclockwise from the +x-axis.)
Magnitude:____N
Direction:_____° counterclockwise from the +x-axis