An electron moves in a circular path perpendicular to a constant magnetic field with a magnitude of$3\mathrm{.}00$mT$.$ The angular momentum of the electron about the center of the circle is$3\mathrm{.}0010-25$J$$s$.$

$($a$)$ Determine the radius of the circular path.

$$cm

$($b$)$ Determine the speed of the electron.

$$m$/$s