Motion is the correct word that fits in.
Hope this helps.
Answer:
New force, 
Explanation:
It is given that,
Force acting between two charged particles, 
We need to find the force if they are moved so they are only one-eighth as far apart.
The force between two charged particles separated at a distance of r is given by :
............(1)
If the charges are one-eighth as far apart then, r' =(1/8)r and new force is given by :
..........(2)
Dividing equation (1) and (2) :


F' = 48000 N
or

Hence, this is the required solution.
When it has a magnetic field