Please note, Keyboard Sensitive system.

Include a clear detailed solution with the formulas used in each step.

make sure that your answer is accurate in a standard form and in scientific notation as well.

4. {15pts} In the gure below, a thin glass rod forms a semicircle of radius r=10.0 cm. Charge is uniformly distributed along the rod, with +q=5.D pC in the upper half and q=5.0 pC in the lower half. What are the (a) magnitude and (b) direction (relative to the positive direction of the x axis) of the electric eld E" at point P, the center of the semicircle? J