Three charges, q1=2.5 μC, q2=2.0 μC and q3=-6.0 μC are placed at positions r1=(-20,10)cm, r2=(0,30)cm and r3=(25,-25)cm.
(a) Calculate the intensity of the electric field produced by q1 and q2 at the point where q3 is.
(b) Calculate the net force on q3.
(c) Calculate the total potential energy of the system of charges.