A long line carrying a uniform linear charge density +50. 0μc/m runs parallel to and 10. 0cm from the surface of a large, flat plastic sheet that has a uniform surface charge density of −100μc/m^2 on one side. Required:
a. Find the location of all points where an α particle would feel no force due to this arrangement of charged objects.
b. Choose an appropriate location of these points at a distance calculated in part A.

1. above the line
2. between the line and the sheet.