How Do You Calculate Bx in a Magnetic Field Problem Involving an Electron?

[sharris203]

Homework Statement

An electron moves through a uniform magnetic field given by B = Bxi+(3.0Bx)j. At a particular instant, the electron has velocity v = (2.0i+4.0j)m/s and the magnetic force acting on it is (6.4x10-19N)k. Find Bx.

Homework Equations

Fb=|q|v x B

The Attempt at a Solution

B = Bxi + (3Bx)j + 0zk
v = 2xi + 4yj + 0zk
Fb = 0xi + 0yj + (6.4 * 10^[-19]N)k

I'm sure I need a matrix. But i can't figure it out, help!

 

[sharris203]

solved.