As you learned in class, charged particles moving in a magnetic field undergo cyclotron motion where they move in circular paths, with the radius determined by the energy of the particle.
(a) Suppose you have a proton (charge q = +e and mass 1.67 x 10^-27 kg) moving in a uniform magnetic field B = 50 mT. If the proton has kinetic energy 120 eV, what is the radius of the cyclotron motion?
(b) Now suppose that we start with the proton outside the magnetic field and we send it flying toward the magnetic field with the same energy (Figure 1). Describe the motion of the particle.
(c) Where will the particle exit the magnetic field? You may assume that the magnetic field extends infinitely far in the up and down directions.
Figure 1:
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