a test charge of +3x10-7 C is located 5cm to the right of a charge of -4x10-6 C and 10 cm to the left of a charge of -1x10-6 C.the three charges lie on a straight line.
(a) find the force on the test charge.
(b) find the intensity and the potential of electric field at this point.
(c) if the test charge is free with what acceleration it will start the motion?