$\}$An ion passing through a $0\mathrm{.}3665$ m magnetic sector instrument with an applied magnetic field of $0\mathrm{.}5$ T feels a centripetal force of

$8\mathrm{.}74$ x $10-15$ N$.$ Use this information to calculate the:

$\}$A$)$ Applied potential in the source

$\}$B$)$ The m$/$z ratio of the ion

$\}$C$)$ The velocity the ion is travelling