A1-kilogram mass is attached to a spring whose constant is 16 N/m, and the entire system is then submerged in a liquid that imparts a damping force numerically equal to 10 times the instantaneous velocity. Determine the equations of motion if

(a) The mass is initially released from rest from a point 1 meter below the equilibrium position, and then

(b) The mass is initially released from a point 1 meter below the equilibrium position with an upward velocity of 12 m/s.