In the figure, a particle moves along a circle in a region of uniform magnetic field of magnitude B = 4.6 mT. The particle is either a proton or an electron (you must decide which). It experiences a magnetic force of magnitude 2.8×10−15 N. What are (a) the particle's speed, (b) the radius of the circle, and (c) the period of the motion? (a) Number Units (b) Number Units (c) Number Units