TheDudeAbides

A Lithium ion with a mass of 1.16 x 10^-26 kg is accelerated through a potential difference of 220 V and than enters a magnetic field with magnitude 0.723 T perpindicular to the path of the ion. What is the radius of the ion's path in the magnetic field? My gut is telling me that I need to find the speed as it enters the magnetic field, from there I could find the radius easily. But I can't find the speed. How to do this question?