In one type of mass spectrometer, ions having the same velocity move through a uniform magnetic field.

Question:

In one type of mass spectrometer, ions having the same velocity move through a uniform magnetic field. The spectrometer is being used to distinguish 12C+ and 14C+ ions that have the same charge. The 12C+ ions move in a circle of diameter 25 cm.
(a) What is the diameter of the orbit of 14C+ ions?
(b) What is the ratio of the frequencies of revolution for the two types of ion?
The conversion between atomic mass units and kilograms is
1 u = 1.66 × 10−27 kg