Before entering a mass spectrometer, ions pass through a velocity selector consisting of parallel plates separated by 2.0 mm and having a potential difference of 160 V. The magnetic field between the plates is 0.42 T. The magnetic field in the mass spectrometer is 1.2 T. Find

(a) The speed of the ions entering the mass spectrometer and

(b) The difference in the diameters of the orbits of singly ionized 238U and 235U. (The mass of a 235U ion is 3.903 × 10^–25 kg.)