Charged particles pass through a velocity selector with electric and magnetic fields at right angles to each

Question:

Charged particles pass through a velocity selector with electric and magnetic fields at right angles to each other, as shown in FIGURE 22-42. If the electric field has a magnitude of 450 N/C and the magnetic field has a magnitude of 0.18 T, what speed must the particles have to pass through the selector undeflected?

Figure 22-42