The aurora is caused when electrons and protons, moving in the earth's magnetic field of ?5×10?5 T, collide with molecules of the atmosphere and cause them to glow. What is the radius of the circular orbit for
(a) an electron with speed 2.0×106m/s and
(b) a proton with spee d 7.0×104m/s.
Radius of the electron and proton in m.