Field and Orbital Frequency Calculation

[brad sue]

Hi, I have this problem that is very difficult for me and I really need some help:

A particle of charge -q and mass m moves in a circular orbital of radius R about a fixed charge Q. The angular frequency for the orbit is given by

wo^2=qQ/(4*pi*(epsilon zero)*m*R^3)

An uniform magnetic field of magnitude B in a direction prependicular to the plane of the orbit is turned on. As a result, the angular frequencyis changed to wo+dw.
Assuming that B is sufficiently small so that products of B and dw can be neglected, calculate dw.
Please can I have some suggestion to start this problem?

Thank you

B

 

[Astronuc]

With just the electric field, the centripetal force of the mass must balance the Coulomb attraction.

Adding a magnetic field imposes a Lorentz force ~ q (v x B) on the moving charge.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/cyclot.html
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/maspec.html#c2

 

[Tide]

I'm not sure whether the problem intends for you to consider this but the addition of the magnetic field changes the kinetic energy of the charge due to the induced EMF of a changing magnetic field.