A body of mass m = 3 gr is attached to a vertical spring with spring constant k = 3 gr/s. Let y be a vertical coordinate with y = 0 at the mass-spring equilibrium position and y be positive downwards. 1. Find the differential equation satisfied by the displacement function y(t). 2. Find the general solution of the differential equation found in part (1). 3. The general solution in part (2) can be written as y(t) = Acos(wt - ), where A > 0, (-T, ], and the frequency, W, is what you found in part (2). At the time t 0 the body is pushed up 3 cm and released with initial velocity downwards of 3 cm/s. Find the amplitude, A, and phase shift, , that describe this solution.