The aurora is caused when electrons and protons, moving in the earth's magnetic field of ≈5.0×10−5t, collide with molecules of the atmosphere and cause them to glow. part a what is the radius of the circular orbit for an electron with speed 3.0×106 m/s ? assume that the electron moves in a plane perpendicular to the magnetic field.

Explanation:

The circular movement is produced by the magnetic field:

This force is a centripetal force because the electron moves in a plane perpendicular to the magnetic field. For a centripetal Force, that produces a circular orbit with a radius r:

If we solve these two equations in order to find r, with the mass and charge of a electron: