Practice Problem on Electric Field for Point Charges



  Q1=+9 micro-C - o--------o Q2=+9 micro-C
                ^ |        |
                | |        |
            3cm | |        |
                | |        |
                | |        |
                | |        |
                v |        |
  Q3=+7 micro-C - o--------o P4           
                  |--2cm---|



3 charges are arranged on a rectangle as shown above. What is the electric field at P4? Give the x and y components, the magnitude, and the direction. Specify the electric field to three significant places and the angle to the nearest integer. Use the convention that right is 0 degrees, up is 90 degrees, left is 180 degrees, and down is 270 degrees.

ANSWER = ( Ex = 1.92e+8 N/C, Ey = -1.42e+8 N/C, |E| = 2.38e+8 N/C, angle = 324 degrees )