$1)$ The energy of electrons in gold is $1\mathrm{.}2$eV below that in vacuum. A gold tip is scanned over a surface and locked at a height where $10\%$ of the electrons tunnel across to the conducting substrate. What is the height of the tip?

a$)1\mathrm{.}1$nm

b$)1\mathrm{.}6$nm

c$)2\mathrm{.}1$nm

d$)2\mathrm{.}6$nm

$2)$ An electron is accelerated out of a sharp tip sticking up vertically, towards a metal plate spaced $100$nm above it held at a voltage of $6$V$.$ What is the estimated force on the electron?

a$)10$pN

b$)1$nN

c$)100$nN

d$)10$N