Two particles with charges q and 2q moving from west to east enter a uniform magnetic field of magnitude B pointing vertically down. The charges have different masses, but the same speed v. In the magnetic field, they move in semicircles with radii R and 2R, respectively.
(a) What is the ratio of their masses?
(b) Is it possible to apply an electric field that would cause the particle of charge q to move in a straight line in the magnetic field? If yes, what is the direction and magnitude of this field?
(c) What effect would this electric field have on the particle of charge 2q?