4 g piece of Styrofoam carries a net charge of 0.5 C and floats above the center of a very large horizontal sheet of plastic that has a uniform...

11.4 g piece of Styrofoam carries a netcharge of −0.5 μC and floats above the centerof a very large horizontal sheet of plastic thathas a uniform charge density on its surface.The acceleration of gravity is 9.8 m/s2and the permittivity of free space is8.85419 × 10−12 C2/N/m2.