$.$ An alpha$-$particle$()$

$2719$

$6\mathrm{.}6410$ kg$,3\mathrm{.}210$ Cm q$$

$==$ travels in a circular path of radius $25$

cm in a uniform magnetic field of magnitude $1\mathrm{.}5$ T$.($a$)$ What is the speed of the particle? $($b$)$

What is the kinetic energy in electron$-$volts? $($c$)$ Through what potential difference must the

particle be accelerated in order to give it this kinetic energy