an electron is released from rest at a distance of 0.300 m from a large insulating sheet of charge that has uniform surface charge density 2.90 * 10-12 c>m2 . (a) how much work is done on the electron by the electric field of the sheet as the electron moves from its initial position to a point 0.050 m from the sheet? (b) what is the speed of the electron when it is 0.050 m from the sheet?