Amass weighing 32 lb stretches a spring 4 ft. the mass is attached to a viscous damper with a damping constant of 4 lb2s/ft. the mass is pushed upward, contracting the spring a distance of 1 ft, and then set in motion with a downward velocity of 4 ft/s. (a) determine the position y of the mass at any time t. (b) find the (or quasi) frequency, period, phase and amplitude of the motion, that is to find wo, t, δ and r from y(t) = rect cos(wot-5). (c) if there is an external force of f(t) 26et lb, in m" ky f(t), what is the general solution (not considering the initial condition)?