Problem $2(20$ pts$)$

lons with charge q and different velocities enter a mass spectrometer. In$,$ Region $1$ there is both a vertical uniform electric field E $($the ty direction$)$ and a uniform magnetic field B in the $+$ direction. Only ions that travel in a straight line make it into Region II$,$ where they are observed to be deflected downward in a circular path with a radius of r$.$

$1.$ Find the speed o of the ions that make it into Region II in terms of the given quantities: V$,$ Bo$,$ and d$.$ First find the magnitude of the electric field E between the capacitor plates charged to potential difference V$.$