A charged particle of mass `m` and charge `q` is released from rest in an electric field of constant magnitude `E`. The kinetic energy of the particle after time `t` is

Options

A. `(2 E^(2) t^(2))/(mq)`
B. `(Et^(2) m)/(2t^(2))`
C. `(E^(2) q^(2) t^(2))/(2m)`
D. `(E q m)/(2t)`

Answer

3

Explanation

`a = (F)/(m) = (qE)/(m)`
`v = u + at = 0 + (qEt)/(m)`
`K = (1)/(2) mv^(2) = (1)/(2) m((qEt)/(m))^(2) = (q^(2) E^(2) t^(2))/(2m)`