$($a$)$ A $-19$ nC charge and a $7$ nC charge are located on the x$-$axis at x$=-6$ cm and x$=1$ cm respectively.

i$.$At what distance $($in cm$)$ directly above the $7$nC charge is the electric potential equal to zero?

$4\mathrm{.}162\mathrm{.}771\mathrm{.}085\mathrm{.}859\mathrm{.}042\mathrm{.}41$

ii$.$What is the electric field $($in N$/$C$)$ at this location $($given as a magnitude and the proper polar angle$)?$

Magnitude

$1\mathrm{.}61$e$+0529700662001\mathrm{.}14$e$+052\mathrm{.}48$e$+0576100$

Angle

$97\mathrm{.}136416723511243\mathrm{.}5$

iii.How far $($in m$)$ to the left of the $-19$nC charge does the electric potential equal $-27$V$?$