# Forces on an Electron

1. Apr 23, 2010

### jand

You have arranged that the magnetic field in a particular region of space is due North with a value of 0.01 T. An electron enters the field traveling to the West with a speed of 0.12 of the speed of light. As a result, the electron experiences a magnetic force which is upwards.

(a) What is the strength of this magnetic force, in fN? (NOTE: The "f" stands for "femto", which is 10^-15.)

(b) What is the amount of the resulting acceleration of the electron?

(c) What will be the result of the acceleration that you have calculated in part (b)?

3. The attempt at a solution

I am really quite lost.. but this is where I thought I should be starting..

Force Law: Fm = |q|vB
where v = .12(1.3 x10^3) m/s , B = .01 T, q = ?? (I'm not sure?)

any help would be appreciated :)
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Apr 23, 2010

### Staff: Mentor

OK.
v is 0.12 times the speed of light. What's the speed of light? (Look it up!)
Good.
What's the charge of an electron? (Look it up!)