A proton is fixed at origin. Another proton is released from rest, from a point at a distance `r` from origin. Taking charge of portion as e and mass as `m`, find the speed of the proton (i) at a distance `2r` from origin (ii) at large distance from origin.

Explanation

The proton moves away under electrostatic repulsion
As there is not external force.
`W_(ext) = 0`
`implies Delta KE + Delta PE = 0` ltbgt `implies ((1)/(2) mv^(2)) + ( U_(r ) - U_(i))= 0`