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. `1/2(q^(2)E^(2)t^(2))/m`
B. `(q^(2)E^(2)t^(2))/m`
C. `1/4(q^(2)E^(2)t^(2))/m`
D. `1/4(q^(2)Et^(2))/m`

Answer

A

Explanation

`F=qE" "therefore"acceleration"=a=(qE)/m`
Velocity = `v=at=(qEt)/m`
`therefore" "K.E.=1/2mv^(2)=1/2(q^(2)E^(2)t^(2))/m`