(Solved): A semicircle of radius \( a \) is in the first and second quadrants, with the center of curvature ...

A semicircle of radius \( a \) is in the first and second quadrants, with the center of curvature at the origin. Positive charge \( +Q \) is distributed uniformly around the left half of the semicircle, and negative charge \( -Q \) is distributed uniformly around the right half of the semicircle in the following figure. Part A What is the magnitude of the net electric field at the origin produced by this distribution of charge? Express your answer in terms of the variables \( Q, a \), and constant \( k \).