Find the electric potential difference AV$,$ required

to stop an electron $($called a "stopping potential"$)$ mov$-$

ing with an initial speed of $2\mathrm{.}85107$ m$/$s$.($b$)$ Would

a proton traveling at the same speed require a greater

or lesser magnitude of electric potential difference?

Explain. $($c$)$ Find a symbolic expression for the ratio

of the proton stopping potential and the electron stop$-$

ping potential, AVp$/$AVe$.$