A horizontal net force FFF is exerted on an object at rest. The object starts at x = 0\,\text mx=0mx, equals, 0, start text, m, end text and has a speed of 4.0\,\dfrac{\text m}{\text s}4.0 s m 4, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction after moving 4.0\,\text m4.0m4, point, 0, start text, m, end text along a horizontal frictionless surface. The net force FFF as a function of the object's position xxx is shown below. What is the mass of the object? Round answer to 2 significant digits. \text {kg}kg