An external force will be applied to the system. Be careful to determine whether the force(s) given in the problem refer to an external force or a damping force or a spring force. Example: A mass weighing 2 lb stretches a spring by 0.5 ft. The spring is displaced 1 ft below the equilibrium and then released. The spring is in a medium that exerts a viscous resistance of 6 lb when the mass has a velocity of 3 ft/sec. The external forcing function is cos(5t). (Assume g = 32 ft/sec^2). Formulate the initial value problem. Do not solve.