Charged particles moved into a B-field

[scrubber]

Homework Statement

Two radioactive isotopes of singly charged plutonium(Pu-249 and Pu-244) are accelerated through a potential difference of 3.00kW and enter a uniform magnetic field of 1.50T directed perpendicular to their velocities. By performing relevat calculations, show that the ratio of the path radii is independent of potential difference and magnetic field.
Given: an atomic mass unit = 1.66*10^-27kg

Homework Equations

R=mv/qB

The Attempt at a Solution

How can I start answering this question?
From the equation, both "v" and "B" are involved. So isn't it dependent?

 

[BvU]

A potential difference of 3 kV I hope ? I don't see this V appear in any of your relevant equations, so you need to find something..

What does that 3kV do to singly charged Pu-249 ? And to Pu-244 ?
You may assume they are at rest before being exposed to this potential difference.