In the figure below, a charged particle moves into a region
ofuniform magnetic field , goes
throughhalf a circle, and then exits that region. The particle is
either aproton or an electron (you must decide which). It spends120
ns in the region.
(a) What is the magnitude of ?
(b) If the particle is sent back through the magnetic field
(alongthe same initial path) but with 5.00times its previous
kinetic energy, how much time does it spend inthe field during this