+1 862 207 3288 mass weighing
A mass weighing 16 pounds stretches a spring 8/3 feet. The mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to ½ the instantaneous velocity. Find the equation of motion if the mass is driven by an external force equal to f (t) = 10 cos 3t.
