A certain spring is found not to obey Hooke's law; it exerts a restoring force Fx(x) = -ax _1Jx2 if it is stretched or compressed where a - 60.0 N/m and f3 - 18.0 N/m2. The mass of 1he spring is negligible.
(a) Calculate 1he potential energy function U(x) for this spring. Let U = 0 when x = O.
(b) An object with mass 0.900 kg on a frictionless, horizontal surface is attached to this spring, pulled a distance 1.00 m to thought (the +x-direction) to stretch 1he spring, and released. What is the speed of 1he object when it is 0.50m to the right of the x = 0 equilibrium position?