Apotential energy function is given by u(x)=(3.00j)x+(1.00j/m^2)x^3. what is the force function f(x) (in newtons) that is associated with this potential energy function? express your answer in terms of x, where x in meters.

Farmer a has a deep well and needs a lot of water for her animals and crops. her neighbor, farmer b, has a shallower well. he needs less water than farmer a because his farm is smaller. in years of drought, sometimes farmer b can't get any water from his wells. what can farmer b do to decrease the likelihood of his well running dry?