A metal sphere of radius 5.00 cm is initially uncharged. How many electrons would have to be placed on the sphere to produce an electric field of magnitude 1.59 105 N/C at a point 7.98 cm from the center of the sphere?

Question

A metal sphere of radius 5.00 cm is initially uncharged. How many electrons would have to be placed on the sphere to produce an electric field of magnitude 1.59  105 N/C at a point 7.98 cm from the center of the sphere?