A thin conducing plate $1\mathrm{.}5m$ on a side is given a total charge of $-20\mathrm{.}0C.($Assume the upward direction is positive.$)$

$($a$)$ What is the electric field $($in $\frac{N}{C})1\mathrm{.}0cm$ above the plate? $($Indicate the direction with the sign of your answer.$)$

$\frac{N}{C}$

$($b$)$ What is the force $($in $N)$ on an electron at this point? $($Indicate the direction with the sign of your answer.$)$

$N$

electric field

$\frac{N}{C}$

force

$N$

$($d$)$ When the electron moves from $1\mathrm{.}0$ to $3\mathrm{.}2cm$ above the plate, how much work $($in J$)$ is done on it by the electric field?

J