QUESTION 1 Rubber tends to be nonlinear as an elastic material. Suppose a particular rubber band exerts a restoring force given by Fx(x) - -AX -Bx4, where the empirical constants are A = 12 N/m and B = 3.7 N/m so that Fx is in newtons when x is in meters. Calculate the change in elastic potential energy of the rubber band when an external force stretches it from x = 0 to x = 0.18 m