1. A force of 9.2x10-14 acts on an unknown particle that travels at 2.40x106 m/s into a magnetic field of 4.8x10-2 T. How many elementary charges does this particle carry? I've used Fm=qvB and found q=Fm/vB and got an answer of q=7.986 x10-19 C. I'm not sure where to go from here. I assume I have to divide by the elementary charge... but I don't know what that is. Haha. 2. An alpha particle with a charge of 3.20x10-19 C and a mass of 6.65 x10-27 kg is travelling at 5.0 x106 m/s. When it enters a magnetic field of 6.4 x10-2 T, a magnetic force provides the centripetal force for the alpha particle. The centripetal force causes the alpha particle to travel in a circular path. Calculate the radius of the circular path. Do I simply use the equation r=(mv)/(qB)?