weight and magnetic force

[kidia]

How can I Compare the magnitudes near the earth’s surface of the weight of an electron and a typical magnetic force exerted by the earth’s magnetic field (B = 10-5T) on an electron with speed 10 m/s.

 

As I understood Weight of electron = mg

Magnetic force=qBv

 

am I right?

[timo]

Mostly. Strictly speaking the magnitude of the magnetic force is qBv*|sin(a)| where a is the angle between the direction of the magnetic field lines and the movement direction of the electron.

But if you´re only interested in the case where the electron moves perpendicular to the field, then your equations are ok.