Question

Which quantity is not required in order to calculate the mass of an ion using a mass spectrometer?O velocity vO magnetic field BO charge qO change in time t

Answer 1

To answer your question, lets think about the formulas needed

Centripetal force = mv^2/r

and force on a point charge = qvb

The force of the magnet is the same on the particle so you can set them equal to each other

qvb = mv^2/r

Set equal to mass

m = qbr/v

Change in time is not needed