When a -3.72*10^-4 C charge
moves from point A to point B, its
electric potential energy increases
by 0.218 J. What is the potential
difference between A and B?
Include the correct sign, + or -
(Unit = v)

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.

This is the answer of your question

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.