(1) A spring with a mass of 2 kg has natural length of 0.5 m. A force of 25.6 N is required to maintain it stretched to a length of 0.7 m. If the spring is stretched to a length of 0.7 m and then released with initial velocity 0, find the position of the mass at any time t. (a) Suppose that the spring is immersed in a fluid with damping constant b = 40. Find the position of the mass at any time t if it starts from the equilibrium position and is given a push to start it with an initial velocity of 0.6 m/s. (2) A spring with a mass of 2 kg has damping constant 14, and a force of 6 N is re- quired to keep the spring stretched 0.5 m beyond its natural length. The spring is stretched 1 m beyond its natural length and then released with zero velocity. Find the position of the mass at any time t. (a) Find the mass that would create critical damping.