Amass weighing 64 lb is attached to a spring hanging from the ceiling and comes to rest at its equilibrium position. at time tequals0, an external force of upper f (t )equals3 cosine 5 t lb is applied to the system. if the spring constant is 10 lb/ft and the damping constant is 2 lb-sec/ft, find the steady-state solution for the system. use g equals 32 ft divided by sec squared.