Three charges are fixed along a line.
Q1 has a charge of +10nC, Q2 has a charge of -4nC, Q 3 is a proton.
The distance between Q1 and Q2 is 3mm and the distance between Q2 and Q3 is 12mm.
(1) Calculate the force acting on the proton (magnitude and direction)
(2)Calculate the electric potential at the position of the proton