# Charged particles in magnetic field

1. Mar 5, 2004

### Aerospace

I've been trying to work this, but the way I'm substituting, I get no variables left...:-\ It's...freaky lol.
The question is
Suppose a new particle is discovered, and it is found that a beam of these particles passes undeflected through "crossed" electric and magnetic fields, where E=316 V/m and B=0.00127 T. If the eleectric field is turned off, the particles moe in the magnetic field in circular paths of radius r=2.97 cm. Determine q/m for the particles from these data. Answer in units of C/kg.

The way I worked this is I used the foruma v=E/B to find the velocity which vame out to be 248818.8976 m/s then I plugged the v into the equation m/q=(rB')/v and since we don't know v or q those remain as variables. Then I plug the values into Em = rB'Bq and so of course, no variables left.

*sighs* help anyone?

2. Mar 5, 2004

### Aerospace

Neverrrrminnddddd lol

I used the v value that I got, and plugged it into r=(mv)/(qB)

:-D thanks ya'll
do help with my other post? lol