Hi, I need help with this question: An ion with a charge-to-mass ratio of 1.10 x 10^4 C/kg travels perpendicular to a magnetic field (B = 9.10 x 10^-1 T) in a circular path (R = 0.240 m). How long does it take the ion to travel one revolution? I've found the speed that it travels....then what? How would I find the distance that it travelled? Do I use the circumference? I've decided....instead of posting a thread everytime I need help, I'm just going to have one thread and this is where I'll post my questions.