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 4.90×10^−12 C/m^2C/m^2.

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?