A mass weighing 4 lb stretches a spring 2 in. Suppose that the mass is given an additional 6 in displacement in the positive direction and then released. The mass is in a medium that exerts a viscous resistance of 6 lb when the mass has a velocity of 3 ft/s. (a) (b) (c) Formulate the initial value problem that governs the motion of the mass-spring system. Solve the IVP to find the equation of motion and sketch the solution curve. Neglecting viscous resistance, find the amplitude and period of the motion and sketch the solution curve.