Answer: I think it’s 20cm.
Explanation:
Relation between potential energy and charge is as follows.
U = qV
or,
=
= J
or, =
Therefore, we can conclude that change in the electrical potential energy is .
It would be D (hoping the picture you posted is what you needed help with
Momentum is a property of moving objects but not stationary objects. You can see this in the formula because momentum equals mass times velocity squared (p=m*v^2). You would not have momentum if you didn't have velocity. Stationary objects have potential energy, and things with potential energy do not have velocity. This is why momentum is a property of moving objects but not of stationary objects.