A 4 kg mass is suspended from by a spring. The spring has the property that a force of 10 N stretches the spring 0:5 m. Let x (t) be the position of the spring at time t: The damping force is equal to 16x 0 (t): The mass is released from the equilibrium position with an initial downward velocity of 4 m/s. Find the position function x (t)