In the gure, a particle moves along a circle in a region of uniform magnetic eld of magnitude B = 4.1 mT. The particle is either a proton or an electron (you must decide which). It experiences a magnetic force of magnitude 3.3 X 10'15 N. What are (a) the particle's speed, (b) the radius of the circle, and (c) the period of the motion? of? j (a) Number 5.03E6 Units m/s (b) Number a 12.8 Units m 1} 4D