Question

four identical charges (q = +3µC) are arranged in a form of a rectangle. what are the magnitude and direction of the net electric force on the charge in the lower right corner attributable to the other three charges? distances are in meters.

Answer 1

Hard to say without knowing the distances... In general F = k Q1 Q2 /|R^2| iin direction of R
If horizontal length = a
and vertical height = h
Q is lower right
Q1 is lower left
Q2 is upper left
Q3 is upper right
R is vector from Q to one of the other 3
Rx = x component of R
Ry = y component of R
then

F1x = k Q Q1/a^2
F1y = 0

F2x = [k Q Q2/(a^2+h^2)] [ a/sqrt(a^2+h^2) ]
F2y = -[ k Q Q2/(a^2+h^2) ] [h/sqrt(a^2+h^2) ]

F3x = 0
F3y = -k Q Q3/h^2

F = F1 + F2 + F3

Answer 2

I do not know