A point charge `q_(0)` is placed at the centre of uniformly charges ring of total charge Q and radius R. If the point charge is slightly displaced with negligible force along axis of the ring then find out its speed when it reaches a large distance.

Explanation

Only electric force is acting on `q_(0)`
`:. W_(el)=DeltaK" "=1/2 mv^(2)-0" "implies" "`Now `W_(el)")"_(c rarr oo) =q_(0) V_(c) =q_(0) (KQ)/R`.
`:. (Kq_(0)Q)/R=1/2 mv^(2)" "implies" "v=sqrt((2Kq_(0)Q)/(mR))`