1. The problem statement, all variables and given/known data An ion is accelerated through potential diff. of 250 V, directly perpendicular to mag. field. Find radius of the path of the ion in the field. Given: mass (m)=2.5 x 10^-26 charge(q)= 1.6 x 10^-19 Volts= 250 V Mag. Field (B) = 0.50 T 2. Relevant equations radius= (mass x VELOCITY)/ (charge x B) 3. The attempt at a solution I know the answer is 1.77 cm for the radius, but i need to prove how, but i cant seem to find an equation or reason to use Volts to get Velocity in the equation.