3. (15) Method of images II Two particles, 1 and 2, with equal charges qı = ½ = q are placed a distance 2b apart.A grounded conducting sphere of radius

a is placed midway between them. (a) What is the Coulomb force on particle 2 due to particle 1 in the absence of the grounded sphere? (b) Determine the net force on particle 2 with the sphere in place; express your answer in terms of a, b, q, and eo. Hint: evaluate an appropriate charge-image system; please draw a sketch of your system including all variable names.(c) What radius (approximated within 1%) must the conducting sphere have in order to neutralize the mutual repulsion of the two charges?Hint: derive an equation for the ratio a/b and try a few values.