Suppose that the particle is an electron projected with velocity `V_(x)=2.0xx10^(6) ms^(-1)`. If E between the plates separated by 0.5 cm is `9.1xx10^(2)N//C`, where will the electron strike the upper plate? `(|e|=1.6xx10^(-19) C, m_(e)=9.1xx10^(-31) kg)`.

Explanation

Let the particle travel a distance x parallel to the plates before striking the upper plate. To strike the plate, the deflection along Y-axis should be 0.5 cm, which is equal to the distance between the plates.
`S=1/2at^2 rArr y=1/2((qE)/m)(x/v_x)^2 rArr x^2=(2myv_x^2)/(qE)`
`=(2xx9.1xx10^(-31)xx0.5xx10^(-2)xx(2xx10^6)^2)/(1.6xx10^(-19)xx9.1xx10^2)`
`rArr x^2=2.5xx10^(-4) rArrx=1.6xx10^(-2)m`=1.6 cm