Three particles have identical masses and identical inital velocities. These particles are projected one at a time into a region in which there is a uniform magnetic field B perpendicular to their velocities. If two of the particles are deflected in opposite directions and the third is not deflected at all, what can you say about them?
Do the two particles that are deflected in opposite directions from each other have the same charge? (like charges repel) But The third charge is neutral because it continues to travel in a line once it enters the uniform magnetic field.