What is the magnitude and direction of the total force on each charge?

Question

Three equal charges, each of +37uC, are spaced along a straight line. Charge A, at one end of the line is 0.55m from the central charge, charge B, and charge C is the other side of charge B a distance of 0.35m from charge B.

Answer 1

F12=kq1q2/R^2

Fa=Fab+Fac
Fb=Fab - Fbc
Fc=Fac+Fbc

Just do the math

Rab=.55m
Rac= .55+ .35=0.90m
Rbc=.35m
k= 8.988 e +9 N m^2 /C^2