Question

Point charges of 22.0 µC and 45.0 µC are placed 0.500 m apart. (a) At what point along the line connecting them is the electric field zero? _____ m (from the smaller charge) (b) What is the magnitude and direction of the electric field halfway between them? ______ N/C toward the smaller charge

Answer 1

q1/r^2 = q2/(d-r)^2

d-r/r = sqrt(q2/q1)

r = d/(1+sqrt(q2/q1)

r = 0.205 m

b) E = E1 - E2 = k*q1/r^2 - k*q2/r^2

E = ((9*10^9)/0.25^2) *(22+45)*10^-6

E = 9648*10^3 = 9.648*10^6 N/C