Two point charges of +60.0 μc and -12.0 μc are separated by a distance of 20.0 cm. what is the magnitude of electric field due to these charges at a point midway between them? (k = 1/4πε 0 = 8.99 × 109 n · m2/c2) two point charges of +60.0 μc and -12.0 μc are separated by a distance of 20.0 cm. what is the magnitude of electric field due to these charges at a point midway between them? (k = 1/4πε 0 = 8.99 × 109 n · m2/c2)

The point midway between the two charges is at 
 
from both charges.

1) Let's calculate the electric field generated by the charge  at the point halfway between the two charges. It will be


2) Instead, the electric field generated by the charge  will be


3) The total field is given by the resultant of the two fields. Now, if we assume that the first charge is on the left of the half-way point and the second charge is on its right, the resultant will be the algebric difference of the two fields, therefore the total field is


and the verse is towards charge 2 (same verse of ).

    5.5 n======    assuming that      we have      m = 0.145 kg    a = 38 m/s²therefore    5.51 n, but two significant figures.final answer: 5.5 n