In a cup of water it is a positive and negative charge of zero
direction ................................................................
The yo-yo speeds up when you rub it
Explanation:
Th electric force between charges is inversely proportional to the square of distance between them. It means,

Initial distance, r₁ = 2 cm
Final distance, r₂ = 0.25 cm
Initial force, F₁ = 1 N
We need to find the electric force between charges if the new separation of 0.25 cm. So,

So, the new force is 64 N if the separation between charges is 64 N.