in a futuristic battle in outer space, a missile of mass 1530 kg is fired with a velocity of 124 m/s at an alien spaceship. The ship is surrounded by a "force field" whose edge is 76.3 m from the ship. The potential energy function of the missile, once it enters the force field, is given by U(x)= 2640(x-76.3)^2 + 1350. what is the force of the force field at x= 40.2 m? How close will the missile get to the spaceship before stopping? ( hint: use conservation of energy)