(a) Calculate the magnitude and direction (relative to the +x-axis) of the electric fiel...

(a) Calculate the magnitude and direction (relative to the +x-axis) of the electric field in Example 21.6. (b) A - 2.5-nC point charge is placed at point P in Fig. 21.19. Find the magnitude and direction of (i) the force that the - 8.0-nC charge at the origin exerts on this charge and (ii) the force that this charge exerts on the - 8.0-nC charge at the origin.