a charged particle enters a uniform magnetic field and follows the circular path shown in the drawing .(a) is the particle positively or negativeiy charged? wfy? (b) the particle s speed is 140 m/s, the magnitude of the magnetic field is 0.48 t, and the radius of the path is 960 m. determine the mass of the particle, given that its charge has a magnitude of 8.2*10^-4 c.[(a) negative; (b) 2.7*10^-3 kg