A small glass bead charged to 8.0 nC is in the plane that bisects a thin, uniformly charged, 10-cm long glass rod and is 4.0 cm from the rod's center. The bead is repelled from the rod with a force of 940 μN. Required:
What is the total charge on the rod?

71nC is the total charge of the rod

Explanation:

See attached file

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

do you have a formula possibly