Three 10-cm-long rods form an equilateral triangle. Two of the rods are charged to + 19 nC, the third to - 19 nC.What is the electric field strength at the center of the triangle?
We calculate the electric field as follows: r = √(3)/6 x 19 cm = .05484 m The angle for the triangle would be 30 on each side. tan(30) = r/(L/2)
E' = kQ/{r*sqrt[(L/2)^2 + r^2]} = (8.99e9 x 15e-9) / {.05484 * sqrt[(.19/2)^2 + .003]} E' = 22413 N/C The value above is the electric field strength for a single rod at the center.