1. The problem statement, all variables and given/known data A certain commercial mass spectrometer is used to separate uranium ions of mass 3.92 10-25 kg and charge 3.20 10-19 C from related species. The ions are accelerated through a potential difference of 140 kV and then pass into a uniform magnetic field, where they are bent in a path of radius 1.10 m. After traveling through 180° and passing through a slit of width 1.00 mm and height 1.00 cm, they are collected in a cup. 2. Relevant equations r = mv/abs(q)B v = sqrt(2qV/m) (where V is potential) 3. The attempt at a solution What is did was first find for velocity using the equation given and I got 478091.4438 then I used the radius equation above and massaged it to B= mv/abs(q)r plugged in my velocity and got .486 this is incorrect why? Also in general when I am ding problems involving magnetic fields how can I easily determine the direction of it I struggle with that.