4. A negatively charged particle of charge q and mass m is accelerated from rest along the x-direction (chosen as horizontal, and positive to the right) by a voltage V. It then enters a magnetic eld region with a uniform magnetic eld B pointing perpendicularly out of the page along the positive zdirection. In this region, there is no electric field. The magnetic field region has a width D in the particle's direction of travel. (a) Draw a sketch of the situation, marking the direction of the electric field, the particle's velocity upon entry into the magnetic eld region, the magnetic eld, the magnetic force on the particle and the particle's velocity at exit from the field region. Mark the center of the particle's trajectory. (b) Set up an expression for the particle's deection, d, in the y-direction, with respect to its direction of travel upon entry into the magnetic field region. This expression should only depend on the cyclotron radius, RC, and D. Once you have this, if D is very small compared to the cyclotron radius, work out an expression for d in terms of B, D, q, m and V