# Conservation of momentum on moving charge

The forces of attraction or repulsion between two stationary charges are the action and reaction forces between them. So when we move one of the charges then the other charge also gets affected. But the force goes in the speed of light. So when one charge is moved apart the force between them decreases. But the other charge can't feel it instantly. So in this time both two charges don't attract other in the same force. So action force isn't equal to reaction force. Thus conservation of momentum is violated. How can this happen?

• Is this actually a question? – DrSheldon Oct 25 '18 at 7:00
• @Dr Sheldon Sorry. Edited now. – Theoretical Oct 25 '18 at 7:08

It turns out that the EM field also contains momentum. In EM the total momentum is conserved including the momentum of the field as well as the mechanical momentum. In CGS units the momentum density of the field is $$\frac{1}{4\pi c}E\times B$$.