A proton (q = 1.6 x 10-19C; m = 1.7 x 10-27 kg) is in a uniform 0.25 T magnetic field. The proton moves in a clockwise circle with a tangential speed of 2.8 x 105 m/s.
What is the radius of the circle?
Not sure what equation to use.
The Attempt at a Solution
We had been learning about magnitude of a magnetic field, and the equation we were working with was B=Fmagnetic/qV, I wasn't sure how to use this to find radius.