Magnetic field due to negative charge

[cuddlesome]

I hope you could help me out with this...

A negative charge q=-7.20mC is moving in a reference frame. When the point charge is at the origin the magnetic field it produces at point (25.o cm,0,0) magnetic field is B= (6.0 x10^(-9)T) j("unit vector") and its speed is 800 m/s . what is the x-.y-. z-components of the velocity of charge??

thanks

 

[Hootenanny]

Well, how do you think we should proceed..?