Calculate the index of refraction of a substance in which light travels at a speed of 2.2x10^8 m/s

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.)

battery with hi vtge high val resist in series