1. A g kg mass is attached to a spring with stiffness k = 16 me. The mass is displaced 1:2 m below the equilibrium point and given a downward velocity of J? mfsec. Neglecting any damping or external forces, write the differential equation that models the problem, determine the equation of motion of the mass, write your answer in the form: MU?) - Rcos(wt 5) Also determine the amplitude of the motion, period and natural frequency