A particle of mass m and charge (-q) enters the region between the two charged plates initially moving along x-axis with speed `V_(x)` (as in the fig.). The length of plate is L and an uniform electric field E is maintained between the plates. Show that the vertical deflection of the particle at the far edge of the plate is `qEL^(2)//(2mV_(x)^(2))`.
Compare this motion with motion of a projectille in gravitational field discussed in section 4.10 of `1^(st)` Year Textbook of Physics.