Electric Fields and Forces
Solution:
a) Calculate the respective electric field due to each individual charge.
Since the electric field due to each charge points to the right, the negative sign is ignored when adding the two values. The negative sign simply indicates the direction of the electric field.
b) The value of the respective electric fields are still the same however, the geometry has changed.
Since the vectors are perpendicular to each other, we simply apply the Pythagorean theorem to calculate the resultant.
c) The forces acting on the charge is given by the formula F = qE or . Since we’ve already calculated the electric field present at point P, we will save ourselves the time of calculating the force acting on the charge due to Q_{1} and Q_{2}, and use the formula F = qE.
The same technique is used to solve the second scenario.
Top of Page 
