How Does Electric Potential Change with Distance from a Charged Sheet?

[adp5025]

Heres the problem:
An infinite nonconducting sheet has a surface charge density of 5.80 pC/m^2. How much work is done by the electric field due to the sheet if a particle of charge q = 1.60x10^-19 C is moved from the sheet to a point P at distance d = 3.56 cm from the sheet? Also if the electric potential V is defined to be zero on the sheet what is V at P.

Ok so here's what i tried doing:

using the equations E = density / 2(8.85E-12) to find E
using E i tried finding Volts using the equation V = EdsCos
after that i used V to solve for Work using the equation
V = -w/q

got nothing close to the answer

as reference the answers in the back of the book say
a) 1.87E-21 J
b)-11.7mV

I don't know what I am doing please help

 

[member 553083]

.Solution:To find the electric field due to the sheet, use the equation E = ρ/2ε₀, where ρ = 5.80 pC/m², ε₀ = 8.85x10^-12 C²/(Nm²). This gives E = 2.58x10^6 N/C. To find the work done by the electric field, use the equation W = qV, where q = 1.60x10^-19 C. The potential at P is V = E•d•cosθ, where d = 3.56 cm and θ = 0° since the charge is being moved perpendicular to the sheet (the electric field due to the sheet is normal to the sheet). This gives a potential of V = -11.7 mV. Finally, the work done is W = qV = 1.87x10^-21 J.