# Homework Help: Stern-Gerlach Separation Distance on Target Film

1. Apr 27, 2009

### Quelsita

I have a question in which we are instructed to find the separation distance between the two impact zones of Sodium atoms on a photographic plate:

A magnet of length l= 0.15m and field gradient $$\nabla$$B= 9.0T/m over its full length is used in a Stern-Gerlach experiment. If a beam of Sodium atoms of velocity v=600m/s passes through this magnet and then strikes a photographic plate at a distance of d=0.80 m beyond the magnet, what will the separation between the two impact zones be on the film?
Sodium has total-angular momentum of J=1/2, contributed by the spin of an electron of the 3s subshell.

I understand that as the electrons enter the magnet, half of the electrons will experience spin-up or spin-down depending if s is positive or negative and thus, there are only two permitted magnetic moments which gives two impact zones on the photo film.
However, I am confused as to how to find the distance between the two impact zones based on the information given.

Any assistance is welcome!
Thanks!

Last edited by a moderator: Apr 27, 2009