3. A 4kg mass is attached to a spring with stiffness factor k=16 N/m. At time t=0, the mass is displaced 1m to the right and set into motion with a velocity in the leftward direction of 2m/sec. Neglect damping. a) Find the equation of motion/position function. b) Express the solution in phase amplitude form x(t) = Acos (wt- a) and tell what the amplitude, period and phase angle are. 4. Using mass-spring analogy decide if the solution is bounded if tco: y"+4y-25cos2t + 6sin2t