Answer:
1/4
Explanation:
If the distance between two charges is doubled, the attraction of repulsion between the two becomes weaker, and decreases to 1/4 of the original value.
Choice - B is the correct one.
At the top of the arc, at one end of the swing:
-- it's not going to get any higher, so the potential energy is maximum
-- it stops moving for an instant, so the kinetic energy is zero
At the bottom of the arc, in the center of the swing:
-- it's not going to get any lower, so the potential energy is minimum
-- it's not going to move any faster, so the kinetic energy is maximum
