PHYSICS HELP PLEASE

Question

Determine magnitude of the electric field at the point P shown in the figure(Figure 1). The two charges are separated by a distance of 2A  from the midpoint between them. Point P is on the perpendicular bisector of the line joining the charges, a distance 

 from the midpoint between them.

Express your answer in terms of Q, x , a, and k

https://session.masteringphysics.com/problemAsset/1737355/1/GIANCOLI.ch21.p48.jpg

   

Answer 1

You can calculate the field at point P due to the positive charge using the standard Coulomb's constant equation to get the magnitude. Then you have to break down the magnitude into the X and Y component directions. Since the charge at point P produced by the positive charge is away from the charge and the charge produced at point P due to the negative charge is toward the negative charge, the X component of each charge will cancel out. However the Y component of each charge will go in the downward direction from each charge so when you calculate the Y component from one charge you just need to double it. So the magnitude of the charge would be KQ1/Distance squared or KQ1/a^2+x^2. But to calculate the Y complement of each charge you would have to multiply it by the sin of the angle whose tangent is equal to a/x, then multiply that by 2. So the final equation becomes 2*KQ/(a^2+X^2) all times sin(tan^-1(a/x)). Sorry but I tried pasting a figure that I created in PowerPoint into this answer but it wouldn't let me.