An infinite sheet has a uniform positive surface charge. Points A and B are located at distances of \(5.0 \mathrm{~cm}\) and \(10.0 \mathrm{~cm}\) from the sheet, respectively.

(a) Is the potential difference \(V_{\mathrm{B}}-V_{\mathrm{A}}\) positive or negative? If the magnitude of this potential difference is \(20.0 \mathrm{~V}\), what is \(\) 

(b) the electric field in the region containing \(\mathrm{A}\) and \(\mathrm{B}\)

(c) the numerical value of the charge density on the sheet?