Two very large parallel sheets are 5.00 cm apart. Sheet A carries a uniform surface charge density of -9.50 µC/m2, and sheet B, which is to the right of A, carries a uniform charge of -11.6 µC/m2. Assume the sheets are large enough to be treated as infinite. Find the magnitude and direction of the net electric field these sheets produce at a point
(a) 4.00 cm to the right of sheet A;
(b) 4.00 cm to the left of sheet A;
(c) 4.00 cm to the right of sheet B.