Abstract
The disturbance of free electron to bounded electron (columb potential) with different free velocity cause changes in potential and velocity of bounded electron when passes nearby. This disturbance increases and decrease both the velocity and potential of the bounded electron. The velocity changes due to repulsion between charges and this repulsion change the distance separation between bounded electron and positively charge electron. After passing away the free electron nearby the bounded electron both velocity and potential are regained due to self-energy of bounded electron. The change in potential is symmetric at the instant because the repulsion distance between bounded and free electron is changed symmetrically.